Further studies on the use of allopurinol to reduce plasma uric acid concentrations in the Red-tailed Hawk ( Buteo jamaicensis ) hyperuricaemic model

Abstract

The present paper reports the effects of allopurinol in a raptor hyperuricaemic model. The study was performed as a follow-up to previous experiments wherein allopurinol was used in doses of 100 and 50 mg/kg, and was proved to be toxic at these higher dose rates. To investigate whether 25 mg/kg (semel in die) s.i.d. allopurinol is a safe and effective dose in Red-tailed Hawks (Buteo jamaicensis) to reduce plasma uric acid concentrations, experimental studies were performed using the physiologically occurring postprandial hyperuricaemia. Preprandial and postprandial plasma concentrations of xanthine, hypoxanthine, allopurinol, oxypurinol and uric acid were established by high-performance liquid chromatography at various time intervals after receiving allopurinol (25 mg/kg SID) or placebo. No significant differences were observed between the experimental and the control group. These results indicate that this dose is safe to administer; however, this dose failed to cause a significant effect on plasma uric acid concentrations. Because of the low therapeutic ratio of allopurinol in Red-tailed Hawks, follow-up studies have concentrated on an alternative for the treatment of hyperuricaemia, namely urate oxidase.

Oxidative stress in ecology and evolution: lessons from avian studies

“…by food supplementation or brood size manipulation. As far as the first two methods are concerned, two recent studies on captive bird species showed that urate oxidase decreases the uric acid concentration more effectively than allopurinol (Poffers et al . 2002a,b).…”

Simultaneous determination of 16 purine derivatives in urinary calculi by gradient reversed-phase high-performance liquid chromatography with UV detection

“…Although numerous reversed-phase chromatographic methods are used for analysis of oxypurines [11,[17][18][19][20][21], methylated purines [18,[22][23][24], 2,8-dihydroxyadenine [12,19,20], allopurinol and oxypurinol [11,[19][20][21]23,25], they are not designed to separate simultaneously all the purines specific for urinary calculi. Original double gradient of pH and methanol content in mobile phase was used, because we could not achieve satisfactory separation of all analytes with constant buffer pH.…”

Clinical Management of Avian Renal Disease

“…Based on the lack of response at a dose of 25 mg/kg and the toxic effects at 50 mg/kg, allopurinol is not recommended in the red-tailed hawk. 27 It is unknown whether this finding should be extrapolated to psittacine birds.…”