Allopurinol Indications and Dosage
- gout
- hyperuricemia
- nephrolithiasis
- renal calculus
- uric acid nephropathy
Allopurinol (Zyloprim) Indications and Dosage
For the treatment of gout (ie., prevention of acute gouty attacks):
NOTE: The lowest effective dose of allopurinol should be used to decrease the incidence of side effects.
Oral dosage:
Adults and children >10 years: Dosages should be adjusted according to patient tolerance and response. Recommended initial dosage is 100 mg PO once daily, increased by 100 mg PO weekly until serum urate concentrations decrease to 6 mg/dL or less, or until reaching a maximum daily dose of 800 mg PO per day. Less severe cases of gout typically require 200-300 mg PO per day. Tophaceous gout typically requires 400-600 mg PO per day. Allopurinol (Zyloprim) therapy should be constant, otherwise serum urate concentrations may increase. The serum uric acid level should be used to indicate the lowest effective dose.
Children <= 10 years: 10 mg/kg/day PO in 2-3 divided doses or 200-300 mg/m2/day PO in 2-4 divided doses. Alternatively, children 6-10 years of age can be given 300 mg/day PO in 2-3 divided doses and children < 6 years of age can be given 150 mg/day PO in 3 divided doses.
For the prevention of acute hyperuricemia during chemotherapy or radiation treatment of leukemia, lymphoma, or solid tumors that may cause tumor lysis syndrome:
NOTE: Intravenous allopurinol has been designated an orphan drug by the FDA for this indication.
Intravenous dosage:
Adults: 200-400 mg/m2/day IV as a single dose or in equally divided infusions at 6-, 8-, or 12, hour intervals. Therapy should be started 24-48 hours prior to the start of chemotherapy, when possible. Doses > 600 mg/day IV do not seem to be more effective than lower doses.
Children: 200 mg/m2/day IV as a single dose or in equally divided infusions at 6-, 8-, or 12-hour intervals. Therapy should be started 24-48 hours prior to the start of chemotherapy, when possible. Doses > 600 mg/day IV do not seem to be more effective than lower doses.
Oral dosage:
Adults and children > 10 years of age: 600-800 mg PO per day in 2-3 divided doses for 2-3 days, beginning 1-2 days before chemotherapy is initiated.
Children between 6-10 years of age: 300 mg/day PO, or 10 mg/kg/day PO, divided up to three times daily for 2-3 days, beginning 1-2 days before chemotherapy is initiated. These dosages should be adjusted after 48 hours, according to patient response.
Children under 6 years of age: 150 mg/day PO in 2-3 divided doses for 2-3 days, beginning 1-2 days before chemotherapy is initiated. These dosages should be adjusted after 48 hours, according to patient response.
For the treatment of uric acid nephropathy (uric acid calculi):
Oral dosage:
Adults and children > 10 years of age: 100-200 mg/day PO up to 4 times per day or 300 mg PO once a day.
Children <= 10 years: 10 mg/kg/day PO in 2-3 divided doses or 200-300 mg/m2/day PO in 2-4 divided doses. Alternatively, children 6-10 years of age can be given 300 mg/day PO in 2-3 divided doses and children < 6 years of age can be given 150 mg/day PO in 3 divided doses.
For the treatment of recurrent calcium oxalate nephrolithiasis (renal calculus) in hyperuricosuric patients:
Oral dosage:
Adults and children > 10 years: 200-300 mg PO once daily or in divided doses. Dosage should be adjusted according to patient response as evidenced by 24-hour urinary urate excretion assays.
Children <= 10 years of age: 10 mg/kg/day PO in 2-3 divided doses, or 200-300 mg/m2/day PO in 2-4 divided doses.
Maximum Dosage Limits:
- Adults: 800 mg/day PO or 600 mg/day IV. Any single oral dose should not exceed 300 mg PO, higher daily dosages should be administered in divided doses.
- Children > 10 years: 800 mg/day PO. Any single oral dose should not exceed 300 mg PO, higher daily dosages should be administered in divided doses. Maximum dosage information is not available for IV dosing.
- Children 6-10 years: 300 mg/day PO; maximum dosage information is not available for IV dosing.
- Children < 6 years: 150 mg/day PO; maximum dosage information is not available for IV dosing.
Patients with hepatic impairment:
Allopurinol (Zyloprim) is primarily metabolized by hepatic oxidation. The drug is known to rarely cause hepatotoxicity, especially if there is preexisting hepatic and/or renal disease. However, specific recommendations for allopurinol dosage adjustment in patients with hepatic impairment are not available.
Patients with renal impairment:
CrCl 100-119 ml/min: maximum dose of 300 mg/day PO.
CrCl 80-99 ml/min: maximum dose of 250 mg/day PO.
CrCl 60-79 ml/min: maximum dose of 200 mg/day PO.
CrCl 40-59 ml/min: maximum dose of 150 mg/day PO.
CrCl 20-39 ml/min: maximum dose of 100 mg/day PO.
CrCl 10-19 ml/min: reduce dose to 100 mg PO every 2 days or 200 mg/day IV.
CrCl 0-9 ml/min: reduce dose to 100 mg PO every 3 days or 100 mg/dose IV, administered at extended intervals.
(adapted from reference.)
[ Last revised: 10/8/2002 12:25:00 PM ]
References
Hande KR, Noone RM, Stone WJ. Severe allopurinol toxicity. Am J Med 1984;76:47-56.
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