Adult Dosing
Chemo-related hyperuricemia
- 200-400 mg/m2/day IV as a single infusion or in divided doses q6-24 hrs
- Max: 600 mg/day
- Start 24-48 hrs prior to chemotherapy and continue until no risk of uric acid overproduction
Pediatric Dosing
Chemo-related hyperuricemia
- 2-10 yrs: 200 mg/m2/day IV as a single infusion or in divided doses q6-24 hrs
- Max: 600 mg/day
- Start 24-48 hrs prior to chemotherapy and continue until no risk of uric acid overproduction
- >10 yrs: 200-400 mg/m2/day IV as a single infusion or in divided doses q6-24 hrs
- Max: 600 mg/day
- Start 24-48 hrs prior to chemotherapy and continue until no risk of uric acid overproduction
[Outline]
Renal Dose Adjustment (Based on CrCl)
- 10-20 mL/min: 200 mg/day IV
- 3-10 mL/min 100 mg/day IV
- <3 mL/min: 100 mg/day IV at extended intervals
Hepatic Dose adjustment
- Hepatic impairment: Dose adjustments not defined; start with lower dose
- Discontinue therapy at first appearance of skin rash or symptom suggestive of an allergic reaction
- Reduce dose of azathioprine and mercaptopurine to one-third to one-fourth if given concomitantly
- Monitor LFTs if hepatic impairment or if anorexia, weight loss, or pruritus develop during therapy
- Periodically perform liver function tests during the early stages of therapy in patients with pre-existing liver disease
- May cause drowsiness. Advise patients to take proper precaution while performing high alert activities
- Concomitant use of thiazides and allopurinol may cause increased hypersensitivity reactions in patients with decreased renal function
- Maintain alkaline nature of urine. Ensure adequate hydration yielding urine output 2L/day to avoid xanthine calculi and renal precipitation of urates in patients using concomitant uricosuric agents
- Alteration in BUN may occur in patients undergoing therapy
- Renal dysfunction may increase in patients with concurrent disease condition such as multiple myeloma and congestive myocardial disease on commencing of therapy
- Renal failure associated with gouty nephropathy and rarely associated with hypersensitivity reactions may occur
- Use lower dose in patients with decreased renal function
- Extend the interval between doses in case of extreme renal impairment
- Bone marrow suppression may occur with the drug
- Monitor BUN/serum creatinine or creatinine clearance at baseline in patients with decreased renal function or having concurrent illness such as hypertension and diabetes mellitus
- Periodically reassess prothrombin time in patients with concurrent use of dicumarol
Cautions: Use cautiously in
- Renal impairment (refer dose adjustment section)
- Hepatic impairment
- Concomitant thiazide diuretics (monitor renal function)
- Concomitant uricosuric agents (may increase excretion of uric acid)
- Concurrent cytotoxic agents
- Bone marrow suppression
- Chemotherapy
- Dehydration
- Geriatric population
- Ampicillin/Amoxicillin administration
Pregnancy Category:C
Breastfeeding: This drug is compatible and considered safe with breastfeeding based upon data from AAP Policy Guidelines (available at http://aappolicy.aappublications.org/cgi/content/full/pediatrics;108/3/776. Allopurinol and its active metabolite oxypurinol are excreted in breast milk. Maternal doses of 300 mg/day provide near therapeutic dose and plasma levels in an exclusively breastfed infant. If allopurinol is required by the mother, it is not a reason to discontinue breastfeeding, but exclusively breastfed infants should be monitored including observation for allergic reactions (rash) and periodic CBC and differential blood counts. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 30 November 2010). Manufacturer advises caution.
