Class: Agent for gout, Antimetabolite
- Powder for injection, lyophilized 500 mg
- Tablets 100 mg
- Tablets 300 mg
Inhibits xanthine oxidase, the enzyme responsible for conversion of hypoxanthine to xanthine and then to uric acid.
About 90% absorbed from GI tract. T max is 1.5 h (allopurinol) and 4.5 h (oxipurinol). C max is 3 mcg/mL (allopurinol 300 mg) and 6.5 mcg/mL (oxipurinol).
Rapidly oxidized to oxipurinol.
About 20% is excreted in the feces. Allopurinol is essentially cleared by glomerular filtration, whereas oxipurinol is reabsorbed in the kidney tubules. T 1/2 , plasma is about 1 to 2 h (allopurinol) and about 15 h (oxipurinol).
Uric acid decreases in about 2 to 3 days.
May require a week or more of treatment.
Xanthine oxidase inhibition is maintained over 24 h; however, uric acid levels may not return to pretreatment levels until 7 to 10 days following cessation of therapy.
Indications and UsageTablets
Treatment of primary or secondary gout, hyperuricemia resulting from chemotherapy for malignancies, recurrent calcium oxalate renal calculi.Tablets and injections
Management of patients with leukemia, lymphoma, and solid tumor malignancies when concurrently receiving cancer therapy that causes elevations of serum and urinary uric acid levels. Use injection in patients who cannot tolerate oral therapy.
Prevention of fluorouracil-induced stomatitis and fluorouracil-induced granulocyte suppression.
Dosage and AdministrationControl of Gout/Hyperuricemia
PO 100 to 800 mg/day. For amounts over 300 mg, give divided doses.Secondary Hyperuricemia Associated with Malignancies
Children 6 to 10 yr of age
PO 300 mg/day.Children under 6 yr of age
PO 150 mg/day.Prevention of Uric Acid Nephropathy in Vigorous Chemotherapy of Neoplastic Disease
PO 600 to 800 mg/day for 2 to 3 days.Reduction of Risk of Acute Gouty Attacks
Adults (initial dose)
PO 100 mg/day, increased by 100 mg at weekly intervals until adequate response is achieved or max recommended dose (800 mg/day) is reached.Leukemia, Lymphoma, Solid Tumor Malignancies
IV 200 to 400 mg/m 2 /day (max 600 mg/day).Children
IV Starting dose 200 mg/m 2 /day.Renal Function Impairment
PO CrCl 10 to 20 mL/min
200 mg/day.CrCl less than 10 mL/min
No more than 100 mg/day.CrCl less than 3 mL/min
100 mg/day at extended intervals.
Alternatively, for CrCl greater than 50 mL/min, use 75% of usual daily dose; CrCl 10 to 50 mL/min, use 50% of usual daily dose; CrCl less than 10 mL/min, use 25% of usual daily dose.IV CrCl 10 to 20 mL/min
200 mg/day.CrCl 3 to 10 mL/min
100 mg/day.CrCl less than 3 mL/min
100 mg/day at extended intervals.
Alternatively, for CrCl greater than 50 mL/min, use 75% of usual daily dose; CrCl 10 to 50 mL/min, use 50% of usual daily dose; CrCl less than 10 mL/min, use 25% of usual daily dose.Hemodialysis
PO/IV Administer 50% of supplemental dose after dialysis. For continuous renal replacement therapy, dose as for CrCl 10 to 50 mL/min.
Store reconstituted solution at 20° to 25°C; do not refrigerate or dilute product.Tablets
Store tablets in tightly closed container in cool location.Unreconstituted solution
Store unreconstituted powder at room temperature.
Drug InteractionsAluminum salts, uricosuric agents
May lessen effectiveness of allopurinol.Ampicillin
May increase incidence of ampicillin-induced skin rash.Cyclophosphamide
May enhance bone marrow suppression.Theophyllines
Theophylline Cl may be decreased, leading to toxicity.Thiopurines (eg, azathioprine, mercaptopurine)
Toxicity of these drugs may be increased.Drugs that are physically incompatible in solution with allopurinol sodium for injection are the following
amikacin; amphotericin B; carmustine; cefotaxime; chlorpromazine; cimetidine; clindamycin; cytarabine; dacarbazine; daunorubicin; diphenhydramine; doxorubicin; doxycycline; droperidol; floxuridine; gentamicin; haloperidol; hydroxyzine; idarubicin; imipenem plus cilastatin; mechlorethamine; meperidine; metoclopramide; methylprednisolone sodium succinate; minocycline; nalbuphine; netilmicin; ondansetron; prochlorperazine edisylate; promethazine; sodium bicarbonate; streptozocin; tobramycin; vinorelbine tartrate.
Laboratory Test Interactions
None well documented.
Drowsiness; generalized seizure (injectable); headache; neuritis; paresthesias; peripheral neuropathy.
Allergic vasculitis; alopecia; ecchymosis; skin rash. Allergic reactions may be severe and sometimes fatal.
Epistaxis; myopathy; taste disturbance.
Abdominal pain; diarrhea; dyspepsia; gastritis; granulomatous changes; nausea; vomiting.
Renal failure; uremia.
Bone marrow depression; eosinophilia; leukocytosis; leukopenia; thrombocytopenia.
Cholestatic jaundice; elevated liver enzymes; hepatic necrosis; hepatitis; reversible hepatomegaly.
Acute gouty attacks; arthralgia; fever; myopathy; necrotizing angiitis.
Category C .
Excreted in breast milk.
Allopurinol is rarely indicated for use in children, except for hyperuricemia resulting from malignancy or with certain rare inborn errors of purine metabolism.
Discontinue drug at first appearance of skin rash or other signs of allergic reaction. Rash may be followed by more severe hypersensitivity reactions and, rarely, death.
Reduced dose is given in patients with this condition. Drug may exacerbate renal failure in certain patients.
Acute gouty attacks
May occur during initial stages of therapy.
Bone marrow depression
Reported in patients given allopurinol.
- Encourage patient to focus on weight loss or control.
- Tell patient to avoid purine-rich foods (eg, organ meats).
- Caution patient to avoid excessive intake of alcohol.
- Explain that gouty attacks may not end for 2 to 6 wk after beginning therapy.
- Instruct patient to stop taking medication and notify health care provider if rash or flu-like symptoms develop.
- Advise patient that drug may cause drowsiness, and to use caution while driving or performing other tasks requiring mental alertness.
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