Allopurinol is used to reduce uric acid in dogs, cats and birds. It is given as a prophylactic treatment of recurrent uric acid uroliths and hyperuricosuric calcium oxalate uroliths in small animals. It has also been used in an attempt to treat gout in pet birds.
Allopurinol has also been recommended as an alternative treatment for canine Leishmaniasis. Although it appears to have clinical efficacy, it does not apparently clear the parasite in most dogs at usual dosages. Allopurinol may also be useful for American trypanosomiasis.
Allopurinol and its metabolite, oxypurinol, inhibit the enzyme xanthine oxidase. Xanthine oxidase is responsible for the conversion of oxypurines to uric acid. Hepatic microsomal enzymes may also be inhibited by alloputinol.
Dosage and Administration:
- Dogs:
- Urate Uroliths
- Dogs: 7-10 mg/kg PO tid for both dissolution and prevention. Goal is to reduce urine
urate:creatinine ratio by 505.
- For Dissolution: 15 mg/kg PO q12h; only in conjunction with low purine foods.
- For Prevention: 10-20 mg/kg/day; because prolonged high doses of allopurinol may result in zanthine uroliths, it may be preferable to minimize recurrence with dietary therapy, with the option of treating infrequent episodes of urate urolith formation with dissolution protocols.
- Alkalinize urine to a pH of 6.5-7 ( see sodium bicarbonate monograph), give
low purine diest and eliminate any UTI, Allopurinol at 10 mg/kg tid for the first
month, then 10 mg/kg once daily thereafter. Reduce dose in patients with renal failure.
- Leishmaniasis
- 15 mg/kg PO twice daily for months
- If possible use with meglumine antimonate, if not use allopurinol alone at 10 mg/kg orally twice daily. If animal has renal insufficiency, use 5 mg/kg twice daily.
- Cats:
- For Urate Uroliths: 9 mg/kg PO per day.
- Birds:
- For Gout: In budgies and cockatiels: Crush one 100 mg tablet into 10 ml of water. Add 20 drops of this solution to ounce of drinking water.
- Reptiles:
- For elevated uric acid levels in renal disease in lizards - 20 mg/kg PO once daily.
Caution:
Use with caution (dosage adjustment may be required) in patients with renal or hepatic dysfunction. Before combining allopurinol with other medication, consider drug interactions by looking at any possible drug interactions by the other medication.
Side Effects: Gastrointestinal effects are the most common, but hepatic and renal effects can occur.
Additional information not available for this medicine.
