ALOPRIM is indicated for the management of adult and pediatric patients with leukemia, lymphoma, and solid tumor malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels and who cannot tolerate oral therapy.

{ "type": "p", "children": [], "text": "ALOPRIM is indicated for the management of adult and pediatric patients with leukemia, lymphoma, and solid tumor malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels and who cannot tolerate oral therapy." }

Initiate therapy with ALOPRIM 24 to 48 hours before the start of chemotherapy known to cause tumor cell lysis. Additionally, administer fluids sufficient to yield a daily urinary output of at least two liters in adults with a neutral or, preferably, slightly alkaline urine.

The recommended daily dose of ALOPRIM is shown in Table 1. Administer the daily dose as single infusion or in equally divided infusions at 6-, 8-, or 12-hour intervals at a rate appropriate for the volume of infusate.

<div class="scrollingtable"><table width="100%"> <caption> <span>Table 1: Recommended Daily Dose of ALOPRIM </span> </caption> <col width="40%"/> <col width="60%"/> <tbody class="Headless"> <tr class="First"> <td class="Botrule Lrule Rrule Toprule" valign="middle"> <p class="First"> <span class="Bold">Adult Patients</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="middle"> <p class="First">200 mg/m<span class="Sup">2</span>/day to 400 mg/m<span class="Sup">2</span>/day intravenously <br/>Maximum 600 mg/day</p> </td> </tr> <tr class="Last"> <td class="Botrule Lrule Rrule Toprule" valign="middle"> <p class="First"> <span class="Bold">Pediatric Patients</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="middle"> <p class="First">Starting Dose 200 mg/m<span class="Sup">2</span>/day intravenously</p> <p>Maximum 400 mg/day</p> </td> </tr> </tbody> </table></div>

The dosage of ALOPRIM to lower serum uric acid to normal or near-normal varies with the severity of the disease. Monitor serum uric acid levels at least daily and administer ALOPRIM at a dose and frequency to maintain the serum uric acid within the normal range. Discontinue ALOPRIM when the patient is able to take oral therapy or when the risk of tumor lysis has abated.

Reduce the dose of ALOPRIM in patients with impaired renal function [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3)]. The recommended dosage reductions of ALOPRIM in adult patients with renal impairment are shown in Table 2.

<div class="scrollingtable"><table width="100%"> <caption> <span>Table 2: Recommended Daily Dose of ALOPRIM in Adult Patients with Renal Impairment</span> </caption> <col width="42%"/> <col width="58%"/> <thead> <tr class="First Last"> <th align="left" class="Botrule Lrule Rrule Toprule" valign="middle"><span class="Bold">Creatinine Clearance</span></th><th align="left" class="Botrule Lrule Rrule Toprule" valign="middle"><span class="Bold">Recommended Daily Dose</span></th> </tr> </thead> <tbody> <tr class="First"> <td class="Botrule Lrule Rrule" valign="middle"> <p class="First">10 to 20 mL/min</p> </td><td class="Botrule Lrule Rrule Toprule" valign="middle"> <p class="First">200 mg/day</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="middle"> <p class="First">Less than 10 mL/min</p> </td><td class="Botrule Lrule Rrule Toprule" valign="middle"> <p class="First">100 mg/day</p> </td> </tr> <tr class="Last"> <td class="Botrule Lrule Rrule Toprule" valign="middle"> <p class="First">On dialysis</p> </td><td class="Botrule Lrule Rrule Toprule" valign="middle"> <p class="First">50 mg every 12 hours, or</p> <p>100 mg every 24 hours</p> </td> </tr> </tbody> </table></div>

Treatment with ALOPRIM has not been studied in pediatric patients with severe renal impairment or on dialysis. For pediatric patients with severe renal impairment or on dialysis, consider the risks and potential benefits before initiating treatment with ALOPRIM [see Warnings and Precautions (5.2) and Use In Specific Populations (8.6)].

Reconstitue and further dilute ALOPRIM prior to intravenous infusion.

Reconstitution

Dilution

Do not mix ALOPRIM with or administer it through the same intravenous port as agents which are incompatible in solution with ALOPRIM. The following table lists drugs that are known to be physically incompatible in solution with ALOPRIM.

<div class="scrollingtable"><table class="Noautorules" width="100%"> <caption> <span>Table 3: Drugs That Are Physically Incompatible in Solution with ALOPRIM</span> </caption> <col width="50%"/> <col width="50%"/> <tbody class="Headless"> <tr> <td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Amikacin sulfate</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Hydroxyzine HCl</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Amphotericin B</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Idarubicin HCl</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Carmustine</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Imipenem-cilastatin sodium</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Cefotaxime sodium</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Mechlorethamine HCl</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Chlorpromazine HCl</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Meperidine HCl</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Cimetidine HCl</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Metoclopramide HCl</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Clindamycin phosphate</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Methylprednisolone sodium succinate</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Cytarabine</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Minocycline HCl</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Dacarbazine</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Nalbuphine HCl </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Daunorubicin HCl</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Ondansetron HCl</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Diphenhydramine HCl</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Prochlorperazine edisylate</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Doxorubicin HCl</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Promethazine HCl</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Doxycycline hyclate</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Sodium bicarbonate</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Droperidol</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Streptozocin</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Floxuridine</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Tobramycin sulfate</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First">Gentamicin sulfate</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Vinorelbine tartrate</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Haloperidol lactate</p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"></td> </tr> </tbody> </table></div>

For Injection: 500 mg of allopurinol as a sterile, white lyophilized powder or cake in a single-dose vial for reconstitution.

{ "type": "p", "children": [], "text": "For Injection: 500 mg of allopurinol as a sterile, white lyophilized powder or cake in a single-dose vial for reconstitution." }

ALOPRIM is contraindicated in patients with a history of severe reaction to any formulation of allopurinol.

{ "type": "p", "children": [], "text": "ALOPRIM is contraindicated in patients with a history of severe reaction to any formulation of allopurinol." }

Serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported in patients taking allopurinol [see Adverse Reactions (6.1)]. These reactions occur in approximately 5 in 10,000 (0.05%) patients taking allopurinol. Other serious hypersensitivity reactions that have been reported include exfoliative, urticarial and purpuric lesions; generalized vasculitis; and irreversible hepatotoxicity. Discontinue ALOPRIM at the first appearance of skin rash or other signs which may indicate a hypersensitivity reaction.

The HLA-B*58:01 allele is a genetic marker for severe skin reactions indicative of hypersensitivity to allopurinol. Patients who carry the HLA-B*58:01 allele are at a higher risk of allopurinol hypersensitivity syndrome (AHS), but hypersensitivity reactions have been reported in patients who do not carry this allele. The frequency of this allele is higher in individuals of African, Asian (e.g., Han Chinese, Korean, Thai), and Native Hawaiian/Pacific Islander ancestry [see Clinical Pharmacology (12.5)]. The use of ALOPRIM is not recommended in HLA-B*58:01 positive patients unless the benefits clearly outweigh the risks.

Prior to starting ALOPRIM, consider testing for the HLA-B*58:01 allele in genetically at-risk populations. Screening is generally not recommended in patients from populations in which the prevalence of HLA-B*58:01 is low, or in current allopurinol users, as the risk of SJS/TEN/DRESS is largely confined to the first few months of therapy, regardless of HLA-B*58:01 status.

Hypersensitivity reactions to ALOPRIM may be increased in patients with decreased renal function receiving thiazide diuretics and ALOPRIM concurrently. In addition, concomitant use of the following drugs may increase the risk of skin rash, which may be severe: bendamustine, thiazide diuretics, ampicillin and amoxicillin [see Drug Interactions (7.1)]. Patients should stop ALOPRIM and seek medical attention if they develop a rash.

Treatment with ALOPRIM may result in renal impairment due to formation of xanthine calculi or due to precipitation of urates in patients receiving concomitant uricosuric agents. Patients with pre-existing renal disease, including renal impairment or history of kidney stones, may be at increased risk for worsening renal impairment due to xanthine calculi or precipitation of urates while receiving treatment with ALOPRIM.

Monitor serum creatinine at least daily during the early stages of allopurinol administration. Maintain fluid intake sufficient to yield a urinary output of at least 2 liters per day in adults. In patients with severely impaired renal function or increase in uric acid concentration associated with decreased urate clearance, reduce the dosage of ALOPRIM [see Use In Specific Populations (8.6) and Dosage and Administration (2.1, 2.2)].

Cases of reversible clinical hepatotoxicity have been noted in patients taking oral allopurinol. In some patients, asymptomatic rises in serum alkaline phosphatase or serum transaminase have been observed. If anorexia, weight loss, or pruritus develop in patients on allopurinol, evaluate liver enzymes. In patients with pre-existing liver disease, monitor liver enzymes periodically during the early stages of therapy. Discontinue ALOPRIM in patients with elevated liver enzymes.

Myelosuppression, manifested by anemia, leukopenia or thrombocytopenia, has been reported in patients receiving allopurinol [see Adverse Reactions (6.1)]. The cytopenias have occurred from as early as 6 weeks to as late as 6 years after the initiation of allopurinol therapy. Discontinue use of ALOPRIM in patients with unexplained cytopenias. Concomitant use with allopurinol with cytotoxic drugs associated with myelosuppression may increase the risk of myelosuppression. Monitor blood counts more frequently [see Drug Interactions (7)].

Concomitant use with allopurinol increases the exposure of either mercaptopurine or azathioprine which may increase the risk of myelosuppression. Reduce the dosage of mercaptopurine or azathioprine as recommended in the respective prescribing information when used concomitantly with ALOPRIM. [see Drug Interactions (7)].

Drowsiness has been reported in patients taking ALOPRIM [see Adverse Reactions (6.1)]. Advise patients to avoid operation of automobiles or other dangerous machinery and activities made hazardous by decreased alertness when starting ALOPRIM or increasing the dose until they know how the drug affects them. Advise patients that the central nervous system depressant effects of ALOPRIM may be additive to those of alcohol and other CNS depressants.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The safety of ALOPRIM was evaluated in an uncontrolled compassionate use study of 1,378 patients with advanced malignancies requiring treatment with cytotoxic chemotherapy and in patients with other serious conditions.

Adverse reactions were reported in 9% (125/1378) of the patients treated with ALOPRIM.

The most common adverse reaction was skin rash. Two patients experience serious adverse reactions (decreased renal function and generalized seizure) and one patient experienced severe diarrhea. Approximately 1.1% of patients experienced allergic adverse reactions (including rash, eosinophilia, local injection site reaction).

A listing of the adverse reactions reported from clinical trials follows:

Incidence Greater Than 1%:

Cutaneous/Dermatologic: rash (1.5%)

Genitourinary: renal failure/insufficiency (1.2%)

Gastrointestinal: nausea (1.3%), vomiting (1.2%)

Incidence Less Than 1%:

Body as a Whole: fever, pain, chills, alopecia, infection, sepsis, enlarged abdomen, mucositis/pharyngitis, blast crisis, cellulitis, hypervolemia

Cardiovascular: heart failure, cardiorespiratory arrest, hypertension, pulmonary embolus, hypotension, decreased venous pressure, flushing, headache, stroke, septic shock, cardiovascular disorder, ECG abnormality, hemorrhage, bradycardia, thrombophlebitis, ventricular fibrillation

Cutaneous/Dermatologic: urticaria, pruritus, local injection site reaction

Gastrointestinal: diarrhea, gastrointestinal bleeding, hyperbilirubinemia, splenomegaly, hepatomegaly, intestinal obstruction, jaundice, flatulence, constipation, liver failure, proctitis

Genitourinary: hematuria, increased creatinine, oliguria, kidney function abnormality, urinary tract infection

Hematologic: leukopenia, marrow aplasia, thrombocytopenia, eosinophilia, neutropenia, anemia, pancytopenia, ecchymosis, bone marrow suppression, disseminated intravascular coagulation

Metabolic: hypocalcemia, hyperphosphatemia, hypokalemia, hyperuricemia, electrolyte abnormality, hypercalcemia, hyperglycemia, hypernatremia, hyponatremia, metabolic acidosis, edema, glycosuria, hyperkalemia, lactic acidosis, water intoxication, hypomagnesemia

Neurologic: seizure, status epilepticus, myoclonus, twitching, agitation, mental status changes, cerebral infarction, coma, dystonia, paralysis, tremor

Pulmonary: respiratory failure/insufficiency, ARDS, increased respiration rate, apnea

Musculoskeletal: arthralgia

Other: hypotonia, diaphoresis, tumor lysis syndrome

Concomitant use of the following drugs may increase the risk of skin rash, which may be severe: bendamustine, thiazide diuretics, ampicillin and amoxicillin. Renal impairment may further increase risk with concomitant use of thiazide diuretics [see Warnings and Precautions (5.1) (5.2) and Clinical Pharmacology (12.2)].

Monitor renal function and reduce the dose of ALOPRIM in patients with concomitant thiazide diuretic use and impaired renal function [see Dosage and Administration (2.2)].

Discontinue ALOPRIM at the first appearance of skin rash or other signs which may indicate a hypersensitivity reaction when use concomitantly with these drugs.

<div class="scrollingtable"><table width="100%"> <caption> <span>Table 4: Interventions for Clinically Important Drug Interactions with ALOPRIM</span> </caption> <col width="19%"/> <col width="81%"/> <tbody class="Headless"> <tr class="First"> <td class="Botrule Lrule Rrule Toprule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Capecitabine</span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Concomitant use with allopurinol may decrease concentration of capecitabine’s active metabolites, which may decrease capecitabine efficacy. </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Avoid the use of ALOPRIM during treatment with capecitabine.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Cyclosporine</span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Concomitant use of allopurinol increases cyclosporine concentrations which may increase the risk of adverse reactions. </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Increase frequency of monitoring cyclosporine concentrations as reflected in the prescribing information when used concomitantly with ALOPRIM.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Cytotoxic Agents </span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Concomitant use of allopurinol with cytotoxic agents increases bone marrow suppression among patients with neoplastic disease, except leukemia <span class="Italics">[see <a href="#ID_d75351f3-b60f-4e8b-8526-3477ecafade6">Warnings and Precautions (5.4)</a> and <a href="#ID_4BF56BF7-34A5-40D1-BC40-F54C504512C0">Clinical Pharmacology (12.2)</a>]</span>.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Blood count monitoring and regular physician follow-up recommended.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Fluorouracil </span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Based on non-clinical data, allopurinol may decrease anti-tumor activity due to suppression of phosphorylation of 5-fluorouracil. </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Concomitant administration with fluorouracil should be avoided.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Mercaptopurine or Azathioprine</span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Allopurinol inhibits xanthine oxidase mediated metabolism of mercaptopurine and azathioprine. Concomitant use of allopurinol increases the exposure of either mercaptopurine or azathioprine which may increase the risk of their adverse reactions including myelosuppression <span class="Italics">[see <a href="#ID_d75351f3-b60f-4e8b-8526-3477ecafade6">Warnings and Precautions (5.4)</a>]</span>.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Reduce the dosage of mercaptopurine or azathioprine as recommended in the respective prescribing information. </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Pegloticase</span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Concomitant use of ALOPRIM and pegloticase may potentially blunt the rise of serum uric acid levels and increase the risk of pegloticase related anaphylaxis in patients whose uric acid level increase to above 6 mg/dL. </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Discontinue and do not institute ALOPRIM therapy during treatment with pegloticase.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Theophylline </span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Concomitant use of allopurinol doses greater than or equal to 600 mg/day may decrease the clearance of theophylline.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Monitor and adjust theophylline doses as reflected in the prescribing information. </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Uricosuric Agents</span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Uricosuric agents increase the excretion of the active allopurinol metabolite oxypurinol. Concomitant use with uricosuric agents decreases oxypurinol exposure which may reduce the inhibition of xanthine oxidase by oxypurinol and increases the urinary excretion of uric acid.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Monitor uric acid levels due to the increased chance of hypouricemic effects.</p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" colspan="2" valign="top"> <p class="First"> <span class="Bold">Warfarin </span> </p> </td> </tr> <tr> <td class="Botrule Lrule Rrule" valign="top"> <p class="First"> <span class="Italics">Clinical Impact</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Allopurinol may inhibit the metabolism of warfarin, possibly enhancing its anticoagulant effect. </p> </td> </tr> <tr class="Last"> <td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First"> <span class="Italics">Intervention</span> </p> </td><td class="Botrule Lrule Rrule Toprule" valign="top"> <p class="First">Patients on concomitant therapy should be monitored for excessive anticoagulation. The INR should be checked frequently and warfarin dosage adjusted accordingly when allopurinol is added to warfarin therapy.</p> </td> </tr> </tbody> </table></div>

Based on findings in animals, ALOPRIM may cause fetal harm when administered to a pregnant woman. Adverse developmental outcomes have been described in exposed animals (see Data). Allopurinol and its metabolite oxypurinol have been shown to cross the placenta following administration of maternal allopurinol.

Available limited published data on allopurinol use in pregnant women do not demonstrate a clear pattern or increase in frequency of adverse developmental outcomes. Among approximately 50 pregnancies described in published literature, 2 infants with major congenital malformations have been reported with following maternal allopurinol exposure. Advise pregnant women of the potential risk to a fetus.

All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

There was no evidence of fetotoxicity or teratogenicity in rats or rabbits treated during the period of organogenesis with oral allopurinol at doses up to 200 mg/kg/day and up to 100 mg/kg/day, respectively (about three times the human dose on a mg/m2 basis). However, there is a published report in pregnant mice that single intraperitoneal doses of 50 or 100 mg/kg (about 1/3 or 3/4 the human dose on a mg/m2 basis) of allopurinol on gestation days 10 or 13 produced significant increases in fetal deaths and teratogenic effects (cleft palate, harelip, and digital defects). It is uncertain whether these findings represented a fetal effect or an effect secondary to maternal toxicity. In another published study with no reported maternal toxicity, allopurinol administered orally at 15 or 45 mg/kg to pregnant rats during organogenesis caused embryonic resorptions, growth retardation, decreased fetal weight, and skeletal, liver, kidney, and brain abnormalities. In rats, maternal treatment with allopurinol in normoxic pregnancy has been shown to increase the cardiac protein levels of sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2a) in the adult male offspring. The mechanism underlying this effect is not understood. However, this effect was not matched by an increase in left ventricular end diastolic pressure or sympathetic dominance in hearts of adult male offspring of normoxic pregnancy treated with allopurinol.

Allopurinol and oxypurinol are present in human milk. Based on information from a single case report, allopurinol and its active metabolite, oxypurinol, were detected in the milk of a mother at five weeks postpartum at an estimated relative infant dose of 0.14 and 0.2 mg/kg of allopurinol and between 7.2 to 8 mg/kg of oxypurinol daily. There was no report of effects of allopurinol on the breastfed infant or on milk production. Because of the potential for serious adverse reactions in a breastfed child, advise women not to breastfeed during treatments with ALOPRIM and for one week after the last dose.

The safety and effectiveness of ALOPRIM have been established in approximately 200 pediatric patients. The efficacy and safety profile observed in this patient population were similar to that observed in adults.

Clinical studies of ALOPRIM did not include sufficient numbers of patients 65 years and older to determine whether they respond differently than younger patients.

Allopurinol and its primary active metabolite, oxypurinol, are eliminated by the kidneys [see Clinical Pharmacology (12.3)]. Therefore, changes in renal function will likely increase allopurinal and oxypurinol exposure. In patients with decreased renal function, or who have concurrent illnesses that can affect renal function such as hypertension and diabetes mellitus, perform periodic laboratory parameters of renal function, particularly BUN and serum creatinine or creatinine clearance, should be performed.

In patients with severely impaired renal function or decreased urate clearance, the half-life of oxypurinol in the plasma is greatly prolonged. Reduce the dose of ALOPRIM in patients with creatinine clearance ≤ 20 mL/min [see Dosage and Administration (2.2)]. Patients should be treated with the lowest effective dose, in order to minimize possible side effects.

In the management of overdosage, there is no specific antidote for ALOPRIM. Both allopurinol and oxypurinol are dialyzable; however, the usefulness of hemodialysis or peritoneal dialysis in the management of an overdose of ALOPRIM is unknown.

{ "type": "p", "children": [], "text": "In the management of overdosage, there is no specific antidote for ALOPRIM. Both allopurinol and oxypurinol are dialyzable; however, the usefulness of hemodialysis or peritoneal dialysis in the management of an overdose of ALOPRIM is unknown." }

ALOPRIM (allopurinol) for Injection, a xanthine oxidase inhibitor, is a sterile, white, lyophilized powder or cake, in a single-dose vial for reconstitution. Each vial contains 500 mg of allopurinol equivalent to 580.7 mg of allopurinol sodium and 148 mg of sodium hydroxide as a solubilizer. Sodium hydroxide is also used as a pH adjuster. ALOPRIM (allopurinol) for Injection contains no preservatives.

{ "type": "p", "children": [], "text": "ALOPRIM (allopurinol) for Injection, a xanthine oxidase inhibitor, is a sterile, white, lyophilized powder or cake, in a single-dose vial for reconstitution. Each vial contains 500 mg of allopurinol equivalent to 580.7 mg of allopurinol sodium and 148 mg of sodium hydroxide as a solubilizer. Sodium hydroxide is also used as a pH adjuster. ALOPRIM (allopurinol) for Injection contains no preservatives." }

Allopurinol is a xanthine oxidase inhibitor. The chemical name for allopurinol sodium is 1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one monosodium salt. It is a white amorphous mass with a molecular weight of 158.09 and molecular formula C5H3N4NaO. The structural formula is:

{ "type": "p", "children": [], "text": "Allopurinol is a xanthine oxidase inhibitor. The chemical name for allopurinol sodium is 1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one monosodium salt. It is a white amorphous mass with a molecular weight of 158.09 and molecular formula C5H3N4NaO. The structural formula is:" }

The pKa of allopurinol sodium is 9.31.

{ "type": "p", "children": [], "text": "The pKa of allopurinol sodium is 9.31." }

Allopurinol is a structural analogue of the natural purine base, hypoxanthine. Allopurinol and its oxypurinol metabolite inhibitor xanthine oxidase, the enzyme responsible for the conversion of hypoxanthine to xanthine and of xanthine to uric acid, the end product of purine metabolism in humans. Allopurinol does not disrupt the biosynthesis of purines.

The action of oral allopurinol differs from that of uricosuric agents, which lower the serum uric acid level by increasing urinary excretion of uric acid. Allopurinol reduces both the serum and urinary uric acid levels by inhibiting the formation of uric acid. The use of allopurinol to block the formation of urates avoids the hazard of increased renal excretion of uric acid posed by uricosuric drugs.

Allopurinol reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding its formation in a dose dependent manner. The pharmacological action of allopurinol is generally believed to be mediated by its oxypurinol metabolite.

Reutilization of both hypoxanthine and xanthine for nucleotide and nucleic acid synthesis is markedly enhanced when their oxidations are inhibited by allopurinol and oxypurinol. This reutilization does not disrupt normal nucleic acid anabolism because feedback inhibition is an integral part of purine biosynthesis. As a result of xanthine oxidase inhibition, the serum concentration of hypoxanthine plus xanthine in patients receiving allopurinol for treatment of hyperuricemia is usually in the range of 0.3 to 0.4 mg/dL compared to a normal level of approximately 0.15 mg/dL. A maximum of 0.9 mg/dL of these oxypurines has been reported when the serum urate was lowered to less than 2 mg/dL by high doses of allopurinol. These values are far below the saturation levels, at which point their precipitation would be expected to occur (above 7 mg/dL). The increased xanthine and hypoxanthine in the urine in patients who were treated with oral allopurinol have not been accompanied by problems of nephrolithiasis; however, there are isolated case reports of xanthine crystalluria.

Based on non-clinical data, allopurinol may decrease anti-tumor activity due to suppression of phosphorylation of 5-fluorouracil.

Concomitant use of ALOPRIM and pegloticase may potentially blunt the rise of serum uric acid levels required for monitoring the safe use of pegloticase.

Enhanced bone marrow suppression by cyclophosphamide and other cytotoxic agents has been reported among patients with neoplastic disease, except leukemia, in the presence of allopurinol.

Reports that the concomitant administration of allopurinol and thiazide diuretics contributed to increased allopurinol toxicity were reviewed; however, a causal mechanism or cause-and-effect relationship was not found.

Following single 100 mg and 300 mg intravenous and oral administration of ALOPRIM, the relative intravenous Cmax was approximately 3-fold and 3.8-fold and AUC0-inf was approximately 1.9-fold higher for allopurinol at both dosages, respectively. The relative intravenous oxypurinol Cmax and AUC0-inf was approximately 1 compaired to oral administration at both dosages.

The Cmax and AUC0- inf for both allopurinol and oxypurinol following intravenous administration of ALOPRIM were dose proportional in the dose range of 100 to 300 mg.

The steady-state allopurinol volume of distribution (mean ± S.D.) is approximately 0.87 ± 0.13 L/Kg following intravenous adminstration.

The half-life (mean ± S.D.) of allopurinol and oxypurinol are approximately 1.21 ± 0.33 and 23.5 ± 4.5 hours following intravenous administration, respectively. The net renal clearance of oxypurinol about 30 mL/min.

Allopurinol is a weak CYP1A2 inhibitor. Allopurinol is rapidly eliminated from the systemic circulation primarily via oxidative metabolism to oxypurinol.

The oxypurinol (alloxanthine) metabolite is also a xanthine oxidase inhibitor and is present in systemic circulation in much higher concentrations and for a much longer period than allopurinol. In general, the ratio of the area under the plasma concentration vs time curve (AUC0-inf) between oxypurinol and allopurinol was in the magnitude of 30 to 40.

Approximately 12% of an allopurinol intravenous dose was excreted unchanged, 76% excreted as oxypurinol, and the remaining dose excreted as riboside conjugates in the urine. Oxypurinol was primarily eliminated unchanged in urine by glomerular filtration and tubular reabsorption.

Concomitant use with allopurinol may decrease concentration of capecitabine’s active metabolites, which may decrease capecitabine efficacy.

Concomitant use of allopurinol increases cyclosporine concentrations which may increase the risk of adverse reactions.

Allopurinol inhibits xanthine oxidase mediated metabolism of mercaptopurine and azathioprine. Concomitant use of allopurinol increases the exposure of either mercaptopurine or azathioprine which may increase the risk of their adverse reactions including myelosuppression.

Concomitant use of allopurinol doses greater than or equal to 600 mg/day may decrease the clearance of theophylline.

Uricosuric agents increase the excretion of the active allopurinol metabolite oxypurinol. Concomitant use with uricosuric agents decreases oxypurinol exposure which may reduce the inhibition of xanthine oxidase by oxypurinol and increases the urinary excretion of uric acid.

Allopurinol may inhibit the metabolism of warfarin, possibly enhancing its anticoagulant effect.

The HLA-B*58:01 allele is a genetic marker for severe skin reactions indicative of hypersensitivity to allopurinol [see Warnings and Precautions (5.1)]. The frequency of the HLA-B*58:01 allele ranges from 8 to 10% in Han Chinese populations, about 8% in Thai populations, and about 6% in Korean populations based upon published literature and available databases. The frequency of the HLA-B*58:01 allele is about 4% in Blacks, about 1-2 % in indigenous peoples of the Americas and Hispanic populations, and <1% in people from European descent and Japanese.

Allopurinol was administered at doses up to 20 mg/kg/day to mice and rats for the majority of their life span. No evidence of carcinogenicity was seen in either mice or rats (at doses about 1/6 or 1/3 the recommended human dose on a mg/m2 basis, respectively).

Allopurinol administered intravenously to rats (50 mg/kg) was not incorporated into rapidly replicating intestinal DNA. No evidence of clastogenicity was observed in an in vivo micronucleus test in rats, or in lymphocytes taken from patients treated with allopurinol (mean duration of treatment 40 months), or in an in vitro assay with human lymphocytes.

Allopurinol oral doses of 20 mg/kg/day had no effect on male or female fertility in rats or rabbits (about 1/3 or 1/2 the human dose on a mg/m2 basis, respectively).

A compassionate use trial of ALOPRIM conducted in the United States from 1977 through 1989 included 718 evaluable patients with malignancies requiring treatment with cytotoxic chemotherapy who were unable to ingest or retain oral medication. Of these patients, 411 had established hyperuricemia and 307 had normal serum urate levels at the time that treatment was initiated. Normal serum uric acid levels were achieved in 68% of the former (reduction of serum uric acid was documented in 93%), and were maintained throughout chemotherapy in 97% of the latter. Because of the study design, it was not possible to assess the impact of the treatment with ALOPRIM on the clinical outcome of the patient groups.

{ "type": "p", "children": [], "text": "A compassionate use trial of ALOPRIM conducted in the United States from 1977 through 1989 included 718 evaluable patients with malignancies requiring treatment with cytotoxic chemotherapy who were unable to ingest or retain oral medication. Of these patients, 411 had established hyperuricemia and 307 had normal serum urate levels at the time that treatment was initiated. Normal serum uric acid levels were achieved in 68% of the former (reduction of serum uric acid was documented in 93%), and were maintained throughout chemotherapy in 97% of the latter. Because of the study design, it was not possible to assess the impact of the treatment with ALOPRIM on the clinical outcome of the patient groups." }

ALOPRIM (allopurinol) for Injection is supplied in 30 mL flint glass single-dose vials. Each vial contains 500 mg of allopurinol as a sterile, white, lyophilized powder or cake for reconstitution.

{ "type": "p", "children": [], "text": "ALOPRIM (allopurinol) for Injection is supplied in 30 mL flint glass single-dose vials. Each vial contains 500 mg of allopurinol as a sterile, white, lyophilized powder or cake for reconstitution." }

NDC 67457-978-50One vial per carton

{ "type": "p", "children": [], "text": "NDC 67457-978-50One vial per carton" }

Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature].

{ "type": "p", "children": [], "text": "Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature]. " }

Skin Rash and Hypersensitivity

{ "type": "p", "children": [], "text": "\nSkin Rash and Hypersensitivity \n" }

Inform patients that ALOPRIM may increase the risk of serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and drug reaction with eosinophilia and systemic symptoms (DRESS). Instruct the patient to be alert for skin rash, blisters, fever or other signs and symptoms of these hypersensitivity reactions. Advise patients to stop the ALOPRIM immediately if they develop any type of rash and seek medical attention [see Warnings and Precautions (5.1)].

{ "type": "p", "children": [], "text": "Inform patients that ALOPRIM may increase the risk of serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and drug reaction with eosinophilia and systemic symptoms (DRESS). Instruct the patient to be alert for skin rash, blisters, fever or other signs and symptoms of these hypersensitivity reactions. Advise patients to stop the ALOPRIM immediately if they develop any type of rash and seek medical attention [see Warnings and Precautions (5.1)]. " }

Renal Function Impairment

{ "type": "p", "children": [], "text": "\nRenal Function Impairment\n" }

Advise patients to stay well hydrated (e.g., 2 liters of liquid per day) while taking ALOPRIM [see Warnings and Precautions (5.2)].

{ "type": "p", "children": [], "text": "Advise patients to stay well hydrated (e.g., 2 liters of liquid per day) while taking ALOPRIM [see Warnings and Precautions (5.2)]." }

Hepatotoxicity

{ "type": "p", "children": [], "text": "\nHepatotoxicity\n" }

Advise patients of the risk of hepatoxicity and to report any signs and symptoms of liver failure, including jaundice, pruritus, bleeding, bruising, or anorexia to their healthcare provider [see Warnings and Precautions (5.3)].

{ "type": "p", "children": [], "text": "Advise patients of the risk of hepatoxicity and to report any signs and symptoms of liver failure, including jaundice, pruritus, bleeding, bruising, or anorexia to their healthcare provider [see Warnings and Precautions (5.3)]." }

Myelosuppression

{ "type": "p", "children": [], "text": "\nMyelosuppression\n" }

Advise patients of the risk of myelosuppression and to report any signs and symptoms of infection, fever, bleeding, shortness of breath, or significant fatigue to their healthcare provider [see Warnings and Precautions (5.4)].

{ "type": "p", "children": [], "text": "Advise patients of the risk of myelosuppression and to report any signs and symptoms of infection, fever, bleeding, shortness of breath, or significant fatigue to their healthcare provider [see Warnings and Precautions (5.4)]." }

Drowsiness

{ "type": "p", "children": [], "text": "\nDrowsiness \n" }

Inform patients that drowsiness has been reported in patients taking ALOPRIM and to be cautious when engaging in activities where alertness is mandatory [see Warnings and Precautions (5.5)].

{ "type": "p", "children": [], "text": "Inform patients that drowsiness has been reported in patients taking ALOPRIM and to be cautious when engaging in activities where alertness is mandatory [see Warnings and Precautions (5.5)]." }

Pregnancy

{ "type": "p", "children": [], "text": "\nPregnancy\n" }

Advise pregnant women of the potential risk to a fetus. Advise women to notify their healthcare provider if they become pregnant or intend to become pregnant during treatment with Aloprim [see Use in Specific Populations (8.1)].

{ "type": "p", "children": [], "text": "Advise pregnant women of the potential risk to a fetus. Advise women to notify their healthcare provider if they become pregnant or intend to become pregnant during treatment with Aloprim [see Use in Specific Populations (8.1)].\n" }

Lactation

{ "type": "p", "children": [], "text": "\nLactation\n" }

Advise women not to breastfeed during treatment with ALOPRIM for one week after the last dose. [see Use in Specific Populations (8.2)].

{ "type": "p", "children": [], "text": "Advise women not to breastfeed during treatment with ALOPRIM for one week after the last dose. [see Use in Specific Populations (8.2)].\n" }

Manufactured for: Mylan Institutional LLC Morgantown, WV 26505 U.S.A.

{ "type": "p", "children": [], "text": "Manufactured for:\nMylan Institutional LLC\nMorgantown, WV 26505 U.S.A." }

Manufactured by: NerPharMa Srl V.le Pasteur 1020014 Nerviano (MI), Italy

{ "type": "p", "children": [], "text": "Manufactured by:\nNerPharMa Srl\nV.le Pasteur 1020014 Nerviano (MI), Italy" }

MI/NP:ALOPIJ:R9 P2119841

{ "type": "p", "children": [], "text": "MI/NP:ALOPIJ:R9 P2119841" }

ALOPRIM is a registered trademark of Mylan Teoranta, a Viatris Company.

{ "type": "p", "children": [], "text": "ALOPRIM is a registered trademark of Mylan Teoranta, a Viatris Company." }

Novaplus is a registered trademark of Vizient, Inc.

{ "type": "p", "children": [], "text": "Novaplus is a registered trademark of Vizient, Inc." }

NDC 67457-978-50

{ "type": "p", "children": [], "text": "NDC 67457-978-50" }

ALOPRIM® (allopurinol) for Injection

{ "type": "p", "children": [], "text": "\nALOPRIM®\n\n(allopurinol)\nfor Injection\n" }

500 mg/vial

{ "type": "p", "children": [], "text": "\n500 mg/vial\n" }

For Intravenous Infusion

{ "type": "p", "children": [], "text": "\nFor Intravenous Infusion\n" }

Sterile

{ "type": "p", "children": [], "text": "\nSterile\n" }

Single-Dose Vial. Discard unused portion.

{ "type": "p", "children": [], "text": "Single-Dose Vial. Discard unused portion." }

Rx ONLY

{ "type": "p", "children": [], "text": "\nRx ONLY\n" }

novaplus+

{ "type": "p", "children": [], "text": "novaplus+\n" }

Each vial contains 500 mg of allopurinol equivalent to 580.7 mg of allopurinol sodium and 148 mg of sodium hydroxide as a solubilizer. Sodium hydroxide is also used as a pH adjuster.

{ "type": "p", "children": [], "text": "Each vial contains 500 mg of allopurinol equivalent to 580.7 mg of allopurinol sodium and 148 mg of sodium hydroxide as a solubilizer. Sodium hydroxide is also used as a pH adjuster." }

Preparation of Solution:

{ "type": "p", "children": [], "text": "\nPreparation of Solution:\n" }

Inject 25 mL Sterile Water for Injection, USP into vial. Swirl vial until solution results. The reconstituted solution contains allopurinol at a concentration of 20 mg/mL. The solution should be stored at 20°C to 25°C (68°F to 77°F) and administration should be completed within 10 hours after reconstitution. Further dilution is required before intravenous administration.

{ "type": "p", "children": [], "text": "Inject 25 mL Sterile Water for Injection, USP into vial. Swirl vial until solution results. The reconstituted solution contains allopurinol at a concentration of 20 mg/mL. The solution should be stored at 20°C to 25°C (68°F to 77°F) and administration should be completed within 10 hours after reconstitution. Further dilution is required before intravenous administration." }

Recommended Dosage: See prescribing information.

{ "type": "p", "children": [], "text": "\nRecommended Dosage: See prescribing information." }

Store at 20°C to 25°C (68°F to 77°F);excursions permitted to 15°C to 30°C(59°F to 86°F) [see USP ControlledRoom Temperature].

{ "type": "p", "children": [], "text": "\nStore at 20°C to 25°C (68°F to 77°F);excursions permitted to 15°C to 30°C(59°F to 86°F) [see USP ControlledRoom Temperature].\n" }

ALOPRIM is a registered trademark of Mylan Teoranta, a Viatris Company.

{ "type": "p", "children": [], "text": "ALOPRIM is a registered trademark of Mylan Teoranta, a Viatris Company." }

Manufactured for: Mylan Institutional LLC Morgantown, WV 26505 U.S.A.

{ "type": "p", "children": [], "text": "Manufactured for:\nMylan Institutional LLC\nMorgantown, WV 26505 U.S.A." }

Made in Italy

{ "type": "p", "children": [], "text": "Made in Italy" }

MI:978:1C:R4

{ "type": "p", "children": [], "text": "MI:978:1C:R4" }

Novaplus is a registered trademark of Vizient, Inc.

{ "type": "p", "children": [], "text": "Novaplus is a registered trademark of Vizient, Inc." }

Allopurinol tablet is indicated for:

{ "type": "p", "children": [], "text": "\nAllopurinol tablet is indicated for:" }

{ "type": "ul", "children": [ "  The management of adults with signs and symptoms of primary or secondary gout (acute attacks, tophi, joint destruction, uric acid lithiasis, and/or nephropathy)", "  The management of adult and pediatric patients with leukemia, lymphoma and solid tumor malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels", "  The management of adult patients with recurrent calcium oxalate calculi whose daily uric acid excretion exceeds 800 mg/day in male patients and 750 mg/day in female patients, despite lifestyle changes (such as reduction of dietary sodium, non-dairy animal protein, oxylate rich foods, refined sugars and increases in oral fluids and fruits and vegetables)" ], "text": "" }

Limitations of Use

{ "type": "p", "children": [], "text": "\nLimitations of Use\n" }

Allopurinol tablets are not recommended for the treatment of asymptomatic hyperuricemia.

{ "type": "p", "children": [], "text": "Allopurinol tablets are not recommended for the treatment of asymptomatic hyperuricemia." }

Prior to initiating treatment with allopurinol in patients with gout, assess the following baseline tests: serum uric acid level, complete blood count, chemistry panel, liver function tests (serum alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase, and total bilirubin), kidney function tests (serum creatinine and eGFR).

Gout flares may occur after initiation of allopurinol tablets due to changing serum uric acid levels resulting in mobilization of urate from tissue deposits. Flare prophylaxis with colchicine or an anti- inflammatory agent according to practice guidelines is recommended upon initiation of allopurinol tablets. While adjusting the dosage of allopurinol tablets in patients who are being treated with colchicine and/or anti-inflammatory agents, continue flare prophylaxis drugs until serum uric acid has been normalized and the patient has been free of gout flares for several months. If a gout flare occurs during allopurinol treatment, allopurinol tablets need not be discontinued. Manage the gout flare concurrently, as appropriate for the individual patient [see Warnings and Precautions (5.2)].

The initial recommended dosage for the management of gout is 100 mg orally daily, with weekly increments of 100 mg, until a serum uric acid level of 6 mg/dL or less is reached. Initiating treatment with lower dosages of allopurinol and titrating slowly, decreases the risk of gout flares and drug induced serious adverse reactions.

In patients with renal impairment the initial dosage is 50 mg orally daily with lower dose increases until serum uric acid level of 6 mg/dL or less is reached. For complete dosage recommendations for patients with renal impairment see Table 1 [see Dosage and Administration (2.6)].

The minimal effective dosage is 100 mg to 200 mg daily and the maximal recommended dosage is 800 mg daily. The appropriate dosage may be administered in divided doses or as a single equivalent dose with the 300 mg tablet. Doses in excess of 300 mg should be administered in divided doses. Monitor patients' kidney function during the early stages of administration of allopurinol tablets and decrease the dosage or withdraw the drug if persistent abnormalities in kidney function occur [see Dosage and Administration (2.6), Warnings and Precautions (5.3), Use in Specific Populations (8.6)].

The dosage of allopurinol tablets to achieve control of gout varies with the severity of the disease. In general, gout control is achieved with 200 mg to 300 mg daily in patients with mild gout, and with 400 mg to 600 mg daily in patients with moderate to severe tophaceous gout. Gout attacks usually become shorter and less severe after several months of therapy.

If a dose of allopurinol tablets is missed, there is no need to double the dose at the next scheduled time. Allopurinol tablets is generally better tolerated if taken following meals. A fluid intake sufficient to yield a daily urinary output of at least 2 liters and the maintenance of a neutral or preferably, slightly alkaline urine are desirable.

Inform patients of the possibility of gout flares [see Warnings and Precautions (5.2)]. Instruct them to remain on allopurinol tablets if this occurs and to increase fluid intake during therapy to prevent kidney stones.

Concurrent Use of Uricosuric Agents

Some patients, may benefit using uricosuric agents concurrently, to reduce serum uric acid to target levels.

When transferring a patient from a uricosuric agent to allopurinol, reduce the dose of the uricosuric agent over a period of several weeks and increase the dose of allopurinol tablets gradually to the required dose needed to maintain target serum uric acid level.

Initiate therapy with allopurinol tablets 24 hours to 48 hours before the start of chemotherapy known to cause tumor cell lysis. Administer fluids sufficient to yield a daily urinary output of at least 2 liters in adults (at least 100 mL/m2/hour in pediatric patients) with a neutral or, preferably, slightly alkaline urine.

The recommended dosage of allopurinol tablets is:

The dosage of allopurinol to maintain normal or near-normal serum uric acid varies with the severity of the disease. Monitor serum uric acid levels at least daily and administer allopurinol at a dose and frequency to maintain the serum uric acid within the normal range. Discontinue allopurinol tablets when the risk of tumor lysis has abated (2 days to 3 days from start of chemotherapy). For complete dosage recommendations for patients with renal impairment, see Table 2 [see Dosage and Administration (2.6)].

The recommended dosage for the management of recurrent calcium oxalate stones in hyperuricosuric patients is 200 mg to 300 mg orally daily in divided doses or as the single equivalent. This dose may be adjusted depending upon the resultant control of the hyperuricosuria based upon subsequent 24-hour urinary urate determinations.

The recommended initial dosages of allopurinol tablets in adult patients with renal impairment are shown in Tables 1 and 2 [see Use in Specific Populations (8.6)].

Patients with Gout

The recommended initial dosages in adult patients with gout with impaired kidney function are shown in Table 1 [see Use in Specific Populations (8.6)].

Initiate treatment with a lower dose of allopurinol and increase the dose gradually in 50 mg/day increments every 2 weeks to 4 weeks in patients with renal impairment to decrease the risk of drug induced serious adverse reactions. Use the lowest dose possible to achieve the desired effect on serum and/or urine uric acid. Monitor kidney function in gout patients with chronic kidney disease closely when initiating treatment with allopurinol and decrease or withdraw the drug if increased abnormalities in kidney function appear and persist.

<div class="scrollingtable"><table class="Noautorules" width="601"> <caption> <span> Table 1. Recommended Initial Dosage in Adult Patients with Gout </span> </caption> <col width="295"/> <col width="306"/> <tbody class="Headless"> <tr> <td align="left" class="Botrule Lrule Rrule Toprule" valign="top"> eGFR<br/> </td><td align="left" class="Botrule Rrule Toprule" valign="top"> Initial Dosage<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"> &gt;60 mL/minute<br/> </td><td align="left" class="Botrule Rrule" valign="top"> No dosage modification<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"> &gt;30 mL/minute to 60 mL/minute<br/> </td><td align="left" class="Botrule Rrule" valign="top"> 50 mg daily<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"> &gt;15 mL/minute to 30 mL/minute<br/> </td><td align="left" class="Botrule Rrule" valign="top"> 50 mg every other day<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"> 5 mL/minute to 15 mL/minute<br/> </td><td align="left" class="Botrule Rrule" valign="top"> 50 mg twice weekly<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"> &lt;5 mL/minute<br/> </td><td align="left" class="Botrule Rrule" valign="top"> 50 mg once weekly<br/> </td> </tr> </tbody> </table></div>

The maximum dosage that should be used in patients with various levels of renal impairment is not defined at different eGFR levels.

Patients with Recurrent Calcium Oxalate Calculi

Data are insufficient to provide dosage recommendations for the treatment of recurrent calcium oxalate calculi in patients with renal impairment. Allopurinol and its metabolites are excreted by the kidney, and accumulation of the drug can occur in renal failure [see Warnings and Precautions (5.3) and Use in Specific Populations (8.6)].

Hyperuricemia Associated with Cancer Therapy

The recommended dosage of allopurinol tablets for the management of hyperuricemia associated with cancer therapy in adult patients with renal impairment is shown in Table 2 [see Use in Specific Populations (8.6)].

<div class="scrollingtable"><table class="Noautorules" width="624"> <caption> <span> Table 2. Recommended Dosage of Allopurinol Tablets in Adult Patients for Management of Hyperuricemia Associated with Cancer Therapy with Renal Impairment </span> </caption> <col width="266"/> <col width="358"/> <tbody class="Headless"> <tr> <td align="center" class="Botrule Lrule Rrule Toprule"> eGFR<br/> </td><td align="center" class="Botrule Rrule Toprule"> Recommended Dosage<br/> </td> </tr> <tr> <td align="center" class="Botrule Lrule Rrule"> &gt;20 mL/min to 60 mL/min<br/> </td><td align="center" class="Botrule Rrule"> No dosage modification<br/> </td> </tr> <tr> <td align="center" class="Botrule Lrule Rrule"> 10 mL/min to 20 mL/min<br/> </td><td align="center" class="Botrule Rrule"> 200 mg/day<br/> </td> </tr> <tr> <td align="center" class="Botrule Lrule Rrule"> &lt;10 mL/min<br/> </td><td align="center" class="Botrule Rrule"> 100 mg/day<br/> </td> </tr> <tr> <td align="center" class="Botrule Lrule Rrule"> On dialysis<br/> </td><td align="center" class="Botrule Rrule"> 50 mg every 12 hours, or<br/> 100 mg every 24 hours<br/> </td> </tr> </tbody> </table></div>

Treatment with allopurinol has not been studied in pediatric patients with severe renal impairment (eGFR <20 mL/min) or on dialysis. There is insufficient information to establish dosing for allopurinol in pediatric patients with renal impairment. In these patients, consider the risks and potential benefits before initiating treatment with allopurinol [see Warnings and Precautions (5.3) and Use in Specific Populations (8.6)].

Allopurinol tablets USP have functional scoring and are available in the following strengths:

{ "type": "p", "children": [], "text": "\nAllopurinol tablets USP have functional scoring and are available in the following strengths:" }

{ "type": "ul", "children": [ "100 mg: White to off-white, round, flat uncoated tablets debossed with '1' on either side of breakline on one side and '209' on other side.", "200 mg: White to off-white, round, flat uncoated tablets debossed with '2' and '0' on either side of the breakline on one side and '09' on the other side.", "300 mg: Light peach to peach colored, spotted, round, flat uncoated tablets debossed with '1' and '2' on either side of the breakline on one side and '10' on the other side." ], "text": "" }

Allopurinol tablets are contraindicated in patients with a history of hypersensitivity reaction to allopurinol or to any of the ingredients of allopurinol tablets.

{ "type": "p", "children": [], "text": "\nAllopurinol tablets are contraindicated in patients with a history of hypersensitivity reaction to allopurinol or to any of the ingredients of allopurinol tablets." }

Serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported in patients taking allopurinol [see Adverse Reactions (6)]. These reactions occur in approximately 5 in 10,000 (0.05%) patients taking allopurinol. Other serious hypersensitivity reactions that have been reported include exfoliative, urticarial and purpuric lesions, generalized vasculitis, and irreversible hepatotoxicity. Discontinue allopurinol permanently at the first appearance of skin rash or other signs which may indicate a hypersensitivity reaction.

The HLA-B*58:01 allele is a genetic marker for severe skin reactions indicative of hypersensitivity to allopurinol. Patients who carry the HLA-B*58:01 allele are at a higher risk of allopurinol hypersensitivity syndrome (AHS), but hypersensitivity reactions have been reported in patients who do not carry this allele. The frequency of this allele is higher in individuals of African, Asian (e.g., Han Chinese, Korean, Thai), and Native Hawaiian/Pacific Islander ancestry [see Clinical Pharmacology (12.5)]. The use of allopurinol is not recommended in HLA- B*58:01 positive patients unless the benefits clearly outweigh the risks.

Consider screening for HLA-B*5801 before starting treatment with allopurinol in patients from populations in which the prevalence of this HLA-B*5801 allele is known to be high. Screening is generally not recommended in patients from populations in which the prevalence of HLA-B*58:01 is low, or in current allopurinol users, as the risk of SJS/TEN/DRESS is largely confined to the first few months of therapy, regardless of HLA- B*58:01 status.

Hypersensitivity reactions to allopurinol may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol concurrently. Concomitant use of the following drugs may also increase the risk of skin rash, which may be severe: bendamustine, ampicillin and amoxicillin [see Drug Interactions (7.1)].

Discontinue allopurinol immediately if a skin rash develops. Instruct patients to stop taking allopurinol tablets immediately and seek medical attention promptly if they develop a rash.

Gout flares have been reported during initiation of treatment with allopurinol, even when normal or subnormal serum uric acid levels have been attained due to the mobilization of urates from tissue deposits. Even with adequate therapy with allopurinol, it may require several months to deplete the uric acid pool sufficiently to achieve control of the flares. The flares typically become shorter and less severe after several months of therapy.

In order to prevent gout flares when treatment with allopurinol is initiated, concurrent prophylactic treatment with colchicine or an anti-inflammatory agent is recommended [see Dosage and Administration (2.2)]. Advise patients to continue allopurinol and prophylactic treatment even if gout flares occur, as it may take months to achieve control of gout flares.

Treatment with allopurinol may result in acute kidney injury due to formation of xanthine calculi or due to precipitation of urates in patients receiving concomitant uricosuric agents. Patients with pre-existing kidney disease, including chronic kidney disease or history of kidney stones, may be at increased risk for worsening of kidney function or acute kidney injury due to xanthine calculi while receiving treatment with allopurinol.

In patients receiving allopurinol for the management of gout or the management of recurrent calcium oxalate calculi, monitor kidney function frequently during the early stages of allopurinol administration. Maintain fluid intake sufficient to yield a urinary output of at least 2 liters per day of neutral or, preferably, slightly alkaline urine to avoid the possibility of formation of xanthine calculi and help prevent renal precipitation of urates in patients receiving concomitant uricosuric agents.

In patients receiving allopurinol for the management of tumor lysis syndrome, monitor kidney function at least daily during the early stages of allopurinol administration. Maintain fluid intake sufficient to yield a urinary output of at least 2 liters per day in adults and at least 2 liters/m2/day (or at least 100 mL/m2/hour) in pediatric patients [see Dosage and Administration (2.4)].

Cases of reversible clinical hepatotoxicity have occurred in patients taking allopurinol, and in some patients, asymptomatic rises in serum alkaline phosphatase or serum transaminase have been observed. If anorexia, weight loss, or pruritus develop in patients on allopurinol, evaluate liver enzymes. In patients with pre-existing liver disease, monitor liver enzymes periodically. Discontinue allopurinol in patients with elevated liver enzymes.

Myelosuppression, manifested by anemia, leukopenia or thrombocytopenia, has been reported in patients receiving allopurinol. The cytopenias have occurred as early as 6 weeks up to 6 years after the initiation of therapy of allopurinol. Concomitant use of allopurinol with cytotoxic drugs associated with myelosuppression may increase the risk of myelosuppression. Monitor blood counts more frequently when cytotoxic drugs are used concomitantly [see Drug Interactions (7.2)].

Concomitant use with allopurinol increases the exposure of either mercaptopurine or azathioprine which may increase the risk of myelosuppression. Reduce the dosage of mercaptopurine or azathioprine as recommended in their respective prescribing information when used concomitantly with allopurinol [see Drug Interactions (7.2)].

Drowsiness, somnolence and dizziness have been reported in patients taking allopurinol [see Adverse Reactions (6)]. Inform patients also that the central nervous system depressant effects of allopurinol may be additive to those of alcohol and other CNS depressants.

Advise patients to avoid operation of automobiles or other dangerous machinery and activities made hazardous by decreased alertness when starting allopurinol or increasing the dose, until they know how the drug affects them.

The following clinically significant adverse reactions are described elsewhere in the labeling:

{ "type": "p", "children": [], "text": "\nThe following clinically significant adverse reactions are described elsewhere in the labeling:" }

{ "type": "ul", "children": [ "Skin Rash and Hypersensitivity [see Warnings and Precautions (5.1)]\n", "Nephrotoxicity [see Warnings and Precautions (5.3)]\n", "Hepatoxicity [see Warnings and Precautions (5.4)]\n", "Myelosuppression [see Warnings and Precautions (5.5)]\n", "Potential Effect on Driving and Use of Machinery [see Warnings and Precautions (5.6)]\n" ], "text": "" }

The following adverse reactions associated with the use of allopurinol were identified in literature, unpublished clinical trials or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The most frequent adverse reaction to allopurinol is skin rash.

{ "type": "p", "children": [], "text": "\nThe following adverse reactions associated with the use of allopurinol were identified in literature, unpublished clinical trials or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The most frequent adverse reaction to allopurinol is skin rash." }

Most Common Adverse Reactions (≥1%)

{ "type": "p", "children": [], "text": "\nMost Common Adverse Reactions (≥1%)\n" }

Gastrointestinal: Diarrhea, nausea, alkaline phosphatase increase, AST/ALT increase.

{ "type": "p", "children": [], "text": "\nGastrointestinal: Diarrhea, nausea, alkaline phosphatase increase, AST/ALT increase." }

Metabolic and Nutritional: Acute attacks of gout.

{ "type": "p", "children": [], "text": "\nMetabolic and Nutritional: Acute attacks of gout. " }

Skin and Appendages: Rash, maculopapular rash.

{ "type": "p", "children": [], "text": "\nSkin and Appendages: Rash, maculopapular rash. " }

Less Common Adverse Reactions (<1%)

{ "type": "p", "children": [], "text": "\nLess Common Adverse Reactions (<1%)" }

Body as a Whole: Ecchymosis, fever, headache, malaise.

{ "type": "p", "children": [], "text": "\nBody as a Whole: Ecchymosis, fever, headache, malaise." }

Cardiovascular: Necrotizing angiitis, vasculitis, pericarditis, peripheral vascular disease, thrombophlebitis, bradycardia, vasodilation.

{ "type": "p", "children": [], "text": "\nCardiovascular: Necrotizing angiitis, vasculitis, pericarditis, peripheral vascular disease, thrombophlebitis, bradycardia, vasodilation." }

Gastrointestinal: Hepatic necrosis, granulomatous hepatitis, hepatomegaly, hyperbilirubinemia, cholestatic jaundice, vomiting, intermittent abdominal pain, gastritis, dyspepsia, hemorrhagic pancreatitis, gastrointestinal bleeding, stomatitis, salivary gland swelling, hyperlipidemia, tongue edema, anorexia.

{ "type": "p", "children": [], "text": "\nGastrointestinal: Hepatic necrosis, granulomatous hepatitis, hepatomegaly, hyperbilirubinemia, cholestatic jaundice, vomiting, intermittent abdominal pain, gastritis, dyspepsia, hemorrhagic pancreatitis, gastrointestinal bleeding, stomatitis, salivary gland swelling, hyperlipidemia, tongue edema, anorexia." }

Hemic and Lymphatic: Thrombocytopenia, eosinophilia, leukocytosis, leukopenia, aplastic anemia, agranulocytosis, eosinophilic fibrohistiocytic lesion of bone marrow, pancytopenia, prothrombin decrease, anemia, hemolytic anemia, reticulocytosis, lymphadenopathy, lymphocytosis.

{ "type": "p", "children": [], "text": "\nHemic and Lymphatic: Thrombocytopenia, eosinophilia, leukocytosis, leukopenia, aplastic anemia, agranulocytosis, eosinophilic fibrohistiocytic lesion of bone marrow, pancytopenia, prothrombin decrease, anemia, hemolytic anemia, reticulocytosis, lymphadenopathy, lymphocytosis." }

Musculoskeletal: Myopathy, arthralgias, myalgia.

{ "type": "p", "children": [], "text": "\nMusculoskeletal: Myopathy, arthralgias, myalgia." }

Nervous: Peripheral neuropathy, neuritis, paresthesia, somnolence, optic neuritis, confusion, dizziness, vertigo, foot drop, decrease in libido, depression, amnesia, tinnitus, asthenia, insomnia.

{ "type": "p", "children": [], "text": "\nNervous: Peripheral neuropathy, neuritis, paresthesia, somnolence, optic neuritis, confusion, dizziness, vertigo, foot drop, decrease in libido, depression, amnesia, tinnitus, asthenia, insomnia." }

Respiratory: Epistaxis, bronchospasm, asthma, pharyngitis, rhinitis.

{ "type": "p", "children": [], "text": "\nRespiratory: Epistaxis, bronchospasm, asthma, pharyngitis, rhinitis." }

Skin and Appendages: Erythema multiforme exudativum (Stevens-Johnson syndrome), toxic epidermal necrolysis (Lyell's syndrome), hypersensitivity vasculitis, purpura, vesicular bullous dermatitis, exfoliative dermatitis, eczematoid dermatitis, pruritus, urticaria, alopecia, onycholysis, lichen planus, furunculosis, facial edema, sweating, skin edema.

{ "type": "p", "children": [], "text": "\nSkin and Appendages: Erythema multiforme exudativum (Stevens-Johnson syndrome), toxic epidermal necrolysis (Lyell's syndrome), hypersensitivity vasculitis, purpura, vesicular bullous dermatitis, exfoliative dermatitis, eczematoid dermatitis, pruritus, urticaria, alopecia, onycholysis, lichen planus, furunculosis, facial edema, sweating, skin edema." }

Special Senses: Taste loss/perversion, cataracts, macular retinitis, iritis, conjunctivitis, amblyopia.

{ "type": "p", "children": [], "text": "\nSpecial Senses: Taste loss/perversion, cataracts, macular retinitis, iritis, conjunctivitis, amblyopia." }

Urogenital: Renal failure, uremia, nephritis, impotence, primary hematuria, albuminuria.

{ "type": "p", "children": [], "text": "\nUrogenital: Renal failure, uremia, nephritis, impotence, primary hematuria, albuminuria." }

Endocrine: Infertility (male), hypercalcemia, gynecomastia (male).

{ "type": "p", "children": [], "text": "\nEndocrine: Infertility (male), hypercalcemia, gynecomastia (male)." }

Concomitant use of the following drugs may increase the risk of skin rash, which may be severe: bendamustine, thiazide diuretics, ampicillin and amoxicillin. Renal impairment may further increase risk with concomitant use of thiazide diuretics [see Warnings and Precautions (5.1, 5.2) and Clinical Pharmacology (12.2)].

Monitor kidney function and reduce the dose of allopurinol in patients with concomitant thiazide diuretic use and impaired renal function [see Dosage and Administration (2.6), Warnings and Precautions (5.1)].

Discontinue allopurinol at the first appearance of skin rash or other signs which may indicate a hypersensitivity reaction when use concomitantly with these drugs [see Warnings and Precautions (5.1)].

<div class="scrollingtable"><table class="Noautorules" width="648"> <caption> <span> Table 3: Interventions for Clinically Important Drug Interactions with Allopurinol</span> </caption> <col width="128"/> <col width="519"/> <tbody class="Headless"> <tr> <td align="left" class="Botrule Lrule Rrule Toprule" colspan="2" valign="top"><span class="Bold"> Capecitabine</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Concomitant use with allopurinol may decrease concentration of capecitabine's active metabolites, which may decrease capecitabine efficacy.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Avoid the use of allopurinol during treatment with capecitabine<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Chlorpropamide</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Allopurinol prolongs the half-life of chlorpropamide as both compete for renal tubular excretion. In patients with renal insufficiency, the risk of hypoglycemia may be increased due to this mechanism.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Monitor patients with renal insufficiency for hypoglycemia when administering chlorpropamide and allopurinol concomitantly.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Cyclosporine</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Concomitant use of allopurinol increases cyclosporine concentrations, which may increase the risk of adverse reactions.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Increase frequency of monitoring cyclosporine concentrations as reflected in its prescribing information and modify the dosage of cyclosporine as appropriate when used concomitantly with allopurinol.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Cyclophosphamide and Other Cytotoxic Agents</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Concomitant use of allopurinol with cyclophosphamide and other cytotoxic agents (doxorubicin, bleomycin, procarbazine, mechloroethamine) increases bone marrow suppression among patients with neoplastic disease, except leukemia.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Blood count monitoring and regular physician follow-up are recommended.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Dicumarol</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Allopurinol prolongs the half-life of the anticoagulant, dicumarol. The mechanism of this drug interaction has not been established but should be noted when allopurinol is given to patients already on dicumarol therapy.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Monitor prothrombin time. Adjust the dosage of dicumarol accordingly when allopurinol is added to anticoagulant therapy.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Fluorouracil</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Based on non-clinical data, allopurinol may decrease anti-tumor activity due to suppression of phosphorylation of 5-fluorouracil.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Concomitant administration with fluorouracil should be avoided.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Mercaptopurine or Azathioprine</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Allopurinol inhibits xanthine oxidase mediated metabolism of mercaptopurine and azathioprine. Concomitant use of allopurinol increases the exposure of either mercaptopurine or azathioprine which may increase the risk of their adverse reactions, including myelosuppression <span class="Italics">[see Warnings and Precautions 5.5].</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> In patients receiving mercaptopurine or azathioprine, the concomitant administration of 300 mg to 600 mg of allopurinol per day will require a reduction in dose to approximately one third to one fourth of the usual dose of mercaptopurine or azathioprine. Subsequent adjustment of doses of mercaptopurine or azathioprine should be made on the basis of therapeutic response and the appearance of toxic effects.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Pegloticase</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Concomitant use of allopurinol and pegloticase may potentially blunt the rise of serum uric acid levels and increase the risk of pegloticase related anaphylaxis in patients whose uric acid level increase to above 6 mg/dL.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Discontinue and do not institute allopurinol therapy during treatment with pegloticase.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Theophylline</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Concomitant use of allopurinol doses greater than or equal to 600 mg/day may decrease the clearance of theophylline<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Monitor and adjust theophylline doses as reflected in the prescribing information.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Uricosuric Drugs</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Uricosuric agents increase the excretion of the active allopurinol metabolite oxypurinol. Concomitant use with uricosuric agents decreases oxypurinol exposure which may reduce the inhibition of xanthine oxidase by oxypurinol and increases the urinary excretion of uric acid.<br/> The net effect of such combined therapy may be useful in some patients in achieving minimum serum uric acid levels provided the total urinary uric acid load does not exceed the competence of the patient's kidney function.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Monitor uric acid levels due to the increased chance of hypouricemic effects.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" colspan="2" valign="top"><span class="Bold"> Warfarin</span> <br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Clinical Impact</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Allopurinol may inhibit the metabolism of warfarin, possibly enhancing its anticoagulant effect.<br/> </td> </tr> <tr> <td align="left" class="Botrule Lrule Rrule" valign="top"><span class="Italics">Intervention</span> <br/> </td><td align="left" class="Botrule Rrule" valign="top"> Monitor patients on concomitant therapy for excessive anticoagulation. Assess INR frequently and adjust warfarin dosage accordingly when allopurinol is added to warfarin therapy.<br/> </td> </tr> </tbody> </table></div>

Risk Summary

Based on findings in animals, allopurinol may cause fetal harm when administered to a pregnant woman. Adverse developmental outcomes have been described in exposed animals (see Data). Allopurinol and its metabolite oxypurinol have been shown to cross the placenta following administration of maternal allopurinol.

Available limited published data on allopurinol use in pregnant women do not demonstrate a clear pattern or increase in frequency of adverse developmental outcomes. Among approximately 50 pregnancies described in published literature, 2 infants with major congenital malformations have been reported with following maternal allopurinol exposure. Advise pregnant women of the potential risk to a fetus.

All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The background risk of major birth defects and miscarriage for the indicated population is unknown.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Data

Human Data

Experience with allopurinol during human pregnancy has been limited partly because women of reproductive age rarely require treatment with allopurinol. A case report published in 2011 described the outcome of a full-term pregnancy in a 35-year-old woman who had recurrent kidney stones since age 18 who took allopurinol throughout the pregnancy. The child had multiple complex birth defects and died at 8 days of life. A second report in 2013 provided data on 31 prospectively ascertained pregnancies involving mothers exposed to allopurinol for varying durations during the first trimester. The overall rate of major fetal malformations and spontaneous abortions was reported to be within the normal expected range; however, one child had severe malformations similar to those described in the cited earlier case report.

Animal Data

There was no evidence of fetotoxicity or teratogenicity in rats or rabbits treated during the period of organogenesis with oral allopurinol at doses up to 200 mg/kg/day and up to 100 mg/kg/day, respectively (about 2.4 times the human dose on a mg/m2 basis). However, there is a published report in pregnant mice that single intraperitoneal doses of 50 mg/kg or 100 mg/kg (about 0.3 or 0.6 times the human dose on a mg/m2 basis) of allopurinol on gestation days 10 or 13 produced significant increases in fetal deaths and teratogenic effects (cleft palate, harelip, and digital defects). It is uncertain whether these findings represented a fetal effect or an effect secondary to maternal toxicity.

Risk Summary

Allopurinol and oxypurinol are present in human milk. Based on information from a single case report, allopurinol and its active metabolite, oxypurinol, were detected in the milk of a mother receiving 300 mg of allopurinol daily at 5 weeks postpartum. The estimated relative infant dose were 0.14 mg/kg and 0.2 mg/kg of allopurinol and between 7.2 mg/kg to 8 mg/kg of oxypurinol daily. There was no report of effects of allopurinol on the breastfed infant or on milk production. Because of the potential for serious adverse reactions in a breastfed child, advise women not to breastfeed during treatments with allopurinol and for one week after the last dose.

Hyperuricemia Associated with Cancer Therapy

The safety and effectiveness of allopurinol for the management of pediatric patients with leukemia, lymphoma and solid tumor malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels have been established in approximately 200 pediatric patients. The efficacy and safety profile observed in this patient population were similar to that observed in adults.

Primary or Secondary Gout

The safety and effectiveness of allopurinol have not been established for the treatment of signs and symptoms of primary or secondary gout in pediatric patients.

Recurrent Calcium Oxalate Calculi

The safety and effectiveness of allopurinol have not been established for the management of pediatric patients with recurrent calcium oxalate calculi.

Inborn Errors of Metabolism

The safety and effectiveness of allopurinol have not been established in pediatric patients with rare inborn errors of purine metabolism.

Allopurinol and its primary active metabolite, oxipurinol, are eliminated by the kidneys; therefore, changes in renal function have a profound effect on exposure. In patients with decreased renal function or who have concurrent illnesses which can affect renal function, perform periodic laboratory parameters of renal function and reassess the patient's dosage of allopurinol [see Dosage and Administration (2.6), Warnings and Precautions (5.3)].

In the management of overdosage there is no specific antidote for allopurinol. Both allopurinol and oxipurinol are dialyzable; however, the usefulness of hemodialysis or peritoneal dialysis in the management of an overdose of allopurinol is unknown.

{ "type": "p", "children": [], "text": "\nIn the management of overdosage there is no specific antidote for allopurinol. Both allopurinol and oxipurinol are dialyzable; however, the usefulness of hemodialysis or peritoneal dialysis in the management of an overdose of allopurinol is unknown." }

Allopurinol is a xanthine oxidase inhibitor. It has the following structural formula:

{ "type": "p", "children": [], "text": "\nAllopurinol is a xanthine oxidase inhibitor. It has the following structural formula:" }

Allopurinol is known chemically as 1,5-dihydro-4H-pyrazolo [3,4-d] pyrimidin-4-oneand it has a molecular weight of 136.11 g/mol. Its solubility in water at 37°C is 80.0 mg/dL and is greater in an alkaline solution. It is a xanthine oxidase inhibitor which is administered orally.

{ "type": "p", "children": [], "text": "\nAllopurinol is known chemically as 1,5-dihydro-4H-pyrazolo [3,4-d] pyrimidin-4-oneand it has a molecular weight of 136.11 g/mol. Its solubility in water at 37°C is 80.0 mg/dL and is greater in an alkaline solution. It is a xanthine oxidase inhibitor which is administered orally." }

Each tablet for oral administration contains either 100 mg, 200 mg or 300 mg of allopurinol, USP and the following inactive ingredients: croscarmellose sodium, colloidal silicon dioxide, lactose monohydrate, magnesium stearate, pregelatinized starch, povidone and FD& C Yellow No. 6 aluminum Lake (only for 300 mg).

{ "type": "p", "children": [], "text": "Each tablet for oral administration contains either 100 mg, 200 mg or 300 mg of allopurinol, USP and the following inactive ingredients: croscarmellose sodium, colloidal silicon dioxide, lactose monohydrate, magnesium stearate, pregelatinized starch, povidone and FD& C Yellow No. 6 aluminum Lake (only for 300 mg)." }

Allopurinol is a structural analogue of the natural purine base, hypoxanthine.

Allopurinol acts on purine catabolism, without disrupting the biosynthesis of purines. It reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding its formation. It is an inhibitor of xanthine oxidase, the enzyme responsible for the conversion of hypoxanthine to xanthine and of xanthine to uric acid, the end product of purine metabolism in humans. Allopurinol is metabolized to the corresponding xanthine analogue, oxypurinol (alloxanthine), which also is an inhibitor of xanthine oxidase.

Allopurinol reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding its formation in a dose dependent manner. The pharmacological action of allopurinol is generally believed to be mediated by its oxypurinol metabolite.

Effect on Hypoxanthine and Xanthine

Reutilization of both hypoxanthine and xanthine for nucleotide and nucleic acid synthesis is markedly enhanced when their oxidations are inhibited by allopurinol and oxipurinol. This reutilization does not disrupt normal nucleic acid anabolism, however, because feedback inhibition is an integral part of purine biosynthesis. As a result of xanthine oxidase inhibition, the serum concentration of hypoxanthine plus xanthine in patients receiving allopurinol for treatment of hyperuricemia is usually in the range of 0.3 mg/dL to 0.4 mg/dL compared to a normal level of approximately 0.15 mg/dL. A maximum of 0.9 mg/dL of these oxypurines has been reported when the serum urate was lowered to less than 2 mg/dL by high doses of allopurinol. These values are far below the saturation levels at which point their precipitation would be expected to occur (above 7 mg/dL). The increased xanthine and hypoxanthine in the urine in patients who were treated with oral allopurinol have not been accompanied by problems of nephrolithiasis; however, there are isolated case reports of xanthine crystalluria.

Drug Interaction Studies

Fluorouracil: Based on non-clinical data, allopurinol may decrease anti-tumor activity due to suppression of phosphorylation of 5-fluorouracil.

Pegloticase: Concomitant use of allopurinol and pegloticase may potentially blunt the rise of serum uric acid levels required for monitoring the safe use of pegloticase.

Cytotoxic Agents: Enhanced bone marrow suppression by cyclophosphamide and other cytotoxic agents has been reported among patients with neoplastic disease, except leukemia, in the presence of allopurinol.

Thiazide Diuretics: Reports that the concomitant administration of allopurinol and thiazide diuretics contributed to increased allopurinol toxicity were reviewed; however, a causal mechanism or cause-and-effect relationship was not found.

Absorption

Allopurinol is approximately 90% absorbed from the gastrointestinal tract. Peak plasma levels generally occur at 1.5 hours and 4.5 hours for allopurinol and oxipurinol respectively. After a single oral dose of 300 mg allopurinol, maximum plasma levels of about 3 mcg/mL of allopurinol and 6.5 mcg/mL of oxipurinol are produced.

Elimination

The half-life of allopurinol and oxipurinol are approximately 1 hour to 2 hours and 15 hours following oral dose of allopurinol, respectively.

Metabolism

Allopurinol is metabolized to the corresponding xanthine analogue, oxypurinol (alloxanthine), which also is an inhibitor of xanthine oxidase.

Excretion

Allopurinol and its primary active metabolite, oxipurinol, are eliminated by the kidneys. Approximately 20% of the ingested allopurinol is excreted in the feces. Oxipurinol is primarily eliminated unchanged in urine by glomerular filtration and tubular reabsorption.

Drug Interaction Studies

Capecitabine: Concomitant use with allopurinol may decrease concentration of capecitabine's active metabolites, which may decrease capecitabine efficacy.

Cyclosporine: Concomitant use of allopurinol increases cyclosporine concentrations which may increase the risk of adverse reactions.

Mercaptopurine or Azathioprine: Allopurinol inhibits xanthine oxidase mediated metabolism of mercaptopurine and azathioprine. Concomitant use of allopurinol increases the exposure of either mercaptopurine or azathioprine which may increase the risk of their adverse reactions including myelosuppression.

Theophylline: Concomitant use of allopurinol doses greater than or equal to 600 mg/day may decrease the clearance of theophylline.

Uricosuric Agents: Uricosuric agents increase the excretion of the active allopurinol metabolite oxypurinol. Concomitant use with uricosuric agents decreases oxypurinol exposure which may reduce the inhibition of xanthine oxidase by oxypurinol and increases the urinary excretion of uric acid.

Warfarin: Allopurinol may inhibit the metabolism of warfarin, possibly enhancing its anticoagulant effect.

HLA-B*5801 allele

The HLA-B*5801 allele is a genetic marker that has shown to be associated with risk of developing allopurinol related hypersensitivity syndrome (DRESS) and SJS/TEN. The frequency of the HLA- B*58:01 allele ranges from 8% to 10% in Han Chinese populations, about 8% in Thai populations, and about 6% in Korean populations based upon published literature and available databases. The frequency of the HLA-B*58:01 allele is about 4% in Blacks, about 1% to 2% in indigenous peoples of the Americas and Hispanic populations, and <1% in people from European descent and Japanese.

Stevens-Johnson syndrome (SJS)/Toxic epidermal necrolysis (TEN) can still occur in patients who are found to be negative for HLA-B*5801 irrespective of ethnic origin.

No evidence of tumorigenicity was observed in male or female mice or rats that received oral allopurinol for the majority of their life spans (greater than 88 weeks) at doses up to 20 mg/kg/day (0.1 and 0.2 times the MRHD on a mg/m2 basis in mice and rats, respectively).

Allopurinol tested negative in the following genotoxicity assays: the in vitro Ames assay, in vitro mouse lymphoma assay, and in vivo rat bone marrow micronucleus assay. Allopurinol administered intravenously to rats (50 mg/kg) was not incorporated into rapidly replicating intestinal DNA. No evidence of clastogenicity was observed in lymphocytes taken from patients treated with allopurinol (mean duration of treatment 40 months), or in an in vitro assay with human lymphocytes.

Allopurinol oral doses of 20 mg/kg/day had no effect on male or female fertility in rats or rabbits (approximately 0.2 or 0.5 times the MRHD on a mg/m2 basis, respectively).

How Supplied

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Allopurinol Tablets USP, 100 mg are white to off-white, round, flat uncoated tablets debossed with '1' on either side of breakline on one side and '209' on other side and are supplied as follows:

{ "type": "p", "children": [], "text": "Allopurinol Tablets USP, 100 mg are white to off-white, round, flat uncoated tablets debossed with '1' on either side of breakline on one side and '209' on other side and are supplied as follows:" }

NDC 70710-1209-1 in bottles of 100 tablets with child-resistant closure

{ "type": "p", "children": [], "text": "NDC 70710-1209-1 in bottles of 100 tablets with child-resistant closure" }

NDC 70710-1209-0 in bottles of 1000 tablets

{ "type": "p", "children": [], "text": "NDC 70710-1209-0 in bottles of 1000 tablets" }

Allopurinol Tablets USP, 200 mg are white to off-white, round, flat uncoated tablets debossed with '2' and '0' on either side of the breakline on one side and '09' on the other side.

{ "type": "p", "children": [], "text": "Allopurinol Tablets USP, 200 mg are white to off-white, round, flat uncoated tablets debossed with '2' and '0' on either side of the breakline on one side and '09' on the other side." }

NDC 70710-2009-9 in bottles of 90 tablets with child-resistant closure

{ "type": "p", "children": [], "text": "NDC 70710-2009-9 in bottles of 90 tablets with child-resistant closure" }

NDC 70710-2009-0 in bottles of 1000 tablets

{ "type": "p", "children": [], "text": "NDC 70710-2009-0 in bottles of 1000 tablets" }

Allopurinol Tablets USP, 300 mg are light peach to peach colored, spotted, round, flat uncoated tablets debossed with '1' and '2' on either side of the breakline on one side and '10' on the other side and are supplied as follows:

{ "type": "p", "children": [], "text": "Allopurinol Tablets USP, 300 mg are light peach to peach colored, spotted, round, flat uncoated tablets debossed with '1' and '2' on either side of the breakline on one side and '10' on the other side and are supplied as follows:" }

NDC 70710-1210-1 in bottles of 100 tablets with child-resistant closure

{ "type": "p", "children": [], "text": "NDC 70710-1210-1 in bottles of 100 tablets with child-resistant closure" }

NDC 70710-1210-5 in bottles of 500 tablets

{ "type": "p", "children": [], "text": "NDC 70710-1210-5 in bottles of 500 tablets" }

NDC 70710-1210-0 in bottles of 1000 tablets

{ "type": "p", "children": [], "text": "NDC 70710-1210-0 in bottles of 1000 tablets" }

Storage and Handling

{ "type": "p", "children": [], "text": "\nStorage and Handling\n" }

Store at 20°C to 25°C (USP Controlled Room Temperature) (68°F to 77°F) in a dry place. Dispense in a tight container as defined in the USP

{ "type": "p", "children": [], "text": "Store at 20°C to 25°C (USP Controlled Room Temperature) (68°F to 77°F) in a dry place. Dispense in a tight container as defined in the USP" }

Administration

{ "type": "p", "children": [], "text": "\nAdministration\n" }

Advise patients to take allopurinol tablets after meals to minimize gastric irritation. If a single dose of allopurinol tablet is occasionally forgotten, there is no need to double the dose at the next scheduled time.

{ "type": "p", "children": [], "text": "Advise patients to take allopurinol tablets after meals to minimize gastric irritation. If a single dose of allopurinol tablet is occasionally forgotten, there is no need to double the dose at the next scheduled time." }

Skin Rash and Hypersensitivity

{ "type": "p", "children": [], "text": "\nSkin Rash and Hypersensitivity\n" }

Inform patients that allopurinol tablets may increase the risk of serious and sometimes fatal dermatologic reactions. Instruct patients to discontinue allopurinol tablets and to seek medical attention immediately, at the first sign of a skin rash, blisters, fever, painful urination, blood in the urine, irritation of the eyes, swelling of the lips or mouth, or other signs and symptoms of hypersensitivity reactions [see Warnings and Precautions (5.1)].

{ "type": "p", "children": [], "text": "Inform patients that allopurinol tablets may increase the risk of serious and sometimes fatal dermatologic reactions. Instruct patients to discontinue allopurinol tablets and to seek medical attention immediately, at the first sign of a skin rash, blisters, fever, painful urination, blood in the urine, irritation of the eyes, swelling of the lips or mouth, or other signs and symptoms of hypersensitivity reactions [see Warnings and Precautions (5.1)].\n" }

Gout Flares During Treatment with Allopurinol

{ "type": "p", "children": [], "text": "\nGout Flares During Treatment with Allopurinol \n" }

Inform patients that gout flares may occur during initiation of treatment with allopurinol, even when their serum uric acid is normal. Concurrent use of additional medications such as colchicine or other anti-inflammatory agents can prevent gout flares. Advise patients to continue treatment with both, allopurinol and the prophylactic therapy as prescribed, even if gout flares occur. Reassure them that it may take months to achieve control of the flares but the flares typically become shorter and less severe after several months of therapy [see Warnings and Precautions (5.2)].

{ "type": "p", "children": [], "text": "Inform patients that gout flares may occur during initiation of treatment with allopurinol, even when their serum uric acid is normal. Concurrent use of additional medications such as colchicine or other anti-inflammatory agents can prevent gout flares. Advise patients to continue treatment with both, allopurinol and the prophylactic therapy as prescribed, even if gout flares occur. Reassure them that it may take months to achieve control of the flares but the flares typically become shorter and less severe after several months of therapy [see Warnings and Precautions (5.2)]." }

Nephrotoxicity

{ "type": "p", "children": [], "text": "\nNephrotoxicity\n" }

Inform patients that allopurinol tablets may affect kidney function. Advise them to increase fluid intake during therapy (i.e., for adults, at least 2 liters of liquids per day) and to stay well hydrated to prevent kidney stones [see Warnings and Precautions (5.3)].

{ "type": "p", "children": [], "text": "Inform patients that allopurinol tablets may affect kidney function. Advise them to increase fluid intake during therapy (i.e., for adults, at least 2 liters of liquids per day) and to stay well hydrated to prevent kidney stones [see Warnings and Precautions (5.3)]." }

Hepatotoxicity

{ "type": "p", "children": [], "text": "\nHepatotoxicity\n" }

Inform patients of the risk of hepatotoxicity and to report to their healthcare provider any signs and symptoms of liver failure, including jaundice, pruritus, bleeding, bruising, or anorexia [see Warnings and Precautions (5.4)].

{ "type": "p", "children": [], "text": "Inform patients of the risk of hepatotoxicity and to report to their healthcare provider any signs and symptoms of liver failure, including jaundice, pruritus, bleeding, bruising, or anorexia [see Warnings and Precautions (5.4)].\n" }

Myelosuppression

{ "type": "p", "children": [], "text": "\nMyelosuppression\n" }

Advise patients of the risk of myelosuppression and to report any signs and symptoms of infection, fever, bleeding, shortness of breath, or significant fatigue to their healthcare provider [see Warnings and Precautions (5.5)].

{ "type": "p", "children": [], "text": "Advise patients of the risk of myelosuppression and to report any signs and symptoms of infection, fever, bleeding, shortness of breath, or significant fatigue to their healthcare provider [see Warnings and Precautions (5.5)].\n" }

Potential Effect on Driving and Use of Machinery

{ "type": "p", "children": [], "text": "\nPotential Effect on Driving and Use of Machinery\n" }

Inform patients that drowsiness, somnolence and dizziness have been reported in patients taking allopurinol tablets. Inform also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. Advise patients to avoid operation of automobiles or other dangerous machinery and activities made hazardous by decreased alertness when starting allopurinol tablets or increasing the dose, until they know how the drug affects them [see Warnings and Precautions (5.6)].

{ "type": "p", "children": [], "text": "Inform patients that drowsiness, somnolence and dizziness have been reported in patients taking allopurinol tablets. Inform also that the central nervous system depressant effects of allopurinol tablets may be additive to those of alcohol and other CNS depressants. Advise patients to avoid operation of automobiles or other dangerous machinery and activities made hazardous by decreased alertness when starting allopurinol tablets or increasing the dose, until they know how the drug affects them [see Warnings and Precautions (5.6)]." }

Risks Associated with Use of Concomitant Medications

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Inform patients that there are risks of adverse effects when allopurinol tablet is used with the following drugs: dicumarol, warfarin, sulfinpyrazone, mercaptopurine, azathioprine, ampicillin, amoxicillin, pegloticase, theophylline, and thiazide diuretics. Advise patients to disclose all medications in use and they should follow the instructions of their physician [see Drug Interactions (7.2)].

{ "type": "p", "children": [], "text": "Inform patients that there are risks of adverse effects when allopurinol tablet is used with the following drugs: dicumarol, warfarin, sulfinpyrazone, mercaptopurine, azathioprine, ampicillin, amoxicillin, pegloticase, theophylline, and thiazide diuretics. Advise patients to disclose all medications in use and they should follow the instructions of their physician [see Drug Interactions (7.2)]." }

Pregnancy

{ "type": "p", "children": [], "text": "\nPregnancy\n" }

Advise pregnant women of the potential risk to a fetus. Advise women to notify their healthcare provider if they become pregnant or intend to become pregnant during treatment with allopurinol tablets [see Use in Specific Populations (8.1)].

{ "type": "p", "children": [], "text": "Advise pregnant women of the potential risk to a fetus. Advise women to notify their healthcare provider if they become pregnant or intend to become pregnant during treatment with allopurinol tablets [see Use in Specific Populations (8.1)].\n" }

Lactation

{ "type": "p", "children": [], "text": "\nLactation\n" }

Advise women not to breastfeed during treatment with allopurinol tablets and for one week after the last dose [see Use in Specific Populations (8.2)].

{ "type": "p", "children": [], "text": "Advise women not to breastfeed during treatment with allopurinol tablets and for one week after the last dose [see Use in Specific Populations (8.2)].\n" }

All trademarks or registered trademarks are the property of their respective owners.

{ "type": "p", "children": [], "text": "All trademarks or registered trademarks are the property of their respective owners." }

Manufactured by:

{ "type": "p", "children": [], "text": "\nManufactured by:\n" }

Zydus Lifesciences Ltd., 

{ "type": "p", "children": [], "text": "\nZydus Lifesciences Ltd., " }

Baddi, India.

{ "type": "p", "children": [], "text": "Baddi, India." }

Distributed by:

{ "type": "p", "children": [], "text": "\nDistributed by:\n" }

Zydus Pharmaceuticals (USA) Inc.

{ "type": "p", "children": [], "text": "\nZydus Pharmaceuticals (USA) Inc.\n" }

Pennington, NJ 08534

{ "type": "p", "children": [], "text": "Pennington, NJ 08534" }

Rev.: 04/25

{ "type": "p", "children": [], "text": "Rev.: 04/25" }

NDC 70710-1209-1 in bottles of 100 tablets

{ "type": "p", "children": [], "text": "\nNDC 70710-1209-1 in bottles of 100 tablets" }

Allopurinol Tablets USP, 100 mg

{ "type": "p", "children": [], "text": "Allopurinol Tablets USP, 100 mg" }

100 Tablets

{ "type": "p", "children": [], "text": "100 Tablets" }

Zydus

{ "type": "p", "children": [], "text": "Zydus" }

Rx only

{ "type": "p", "children": [], "text": "Rx only" }

NDC 70710-1210-1 in bottles of 100 tablets

{ "type": "p", "children": [], "text": "\nNDC 70710-1210-1 in bottles of 100 tablets" }

Allopurinol Tablets USP, 300 mg

{ "type": "p", "children": [], "text": "Allopurinol Tablets USP, 300 mg" }

100 Tablets

{ "type": "p", "children": [], "text": "100 Tablets" }

Zydus

{ "type": "p", "children": [], "text": "Zydus" }

Rx only

{ "type": "p", "children": [], "text": "Rx only" }

NDC 70710-2009-9 in bottles of 90 tablets

{ "type": "p", "children": [], "text": "\nNDC 70710-2009-9 in bottles of 90 tablets" }

Allopurinol Tablets USP, 200 mg

{ "type": "p", "children": [], "text": "Allopurinol Tablets USP, 200 mg" }

90 Tablets

{ "type": "p", "children": [], "text": "90 Tablets" }

Zydus

{ "type": "p", "children": [], "text": "Zydus" }

Rx only

{ "type": "p", "children": [], "text": "Rx only" }