INVESTIGATION OF ANALGESIC ACTIVITY OF XANTHINE OXIDASE INHIBITOR ALLOPURINOL: AN EXPERIMENTAL STUDY
Keywords:Analgesic, Allopurinol, Purines, Tail-flick method, Xanthine oxidase inhibitor
Objectives: To investigate the analgesic activity of xanthine oxidase inhibitor, allopurinol in three graded doses and compare it with control and aspirin.
Methods: Analgesic effect of allopurinol in three graded doses (100, 200, 400 mg/kg I. P.), aspirin in analgesic dose (100mg/kg I. P.) and tramadol was evaluated by using Radiant heat Tail-flick method and Acetic-acid induced writhing method in albino rats and mice respectively. The results were analyzed statistically by ANOVA followed by Dunnet's test.
Results: Allopurinol possesses significant analgesic activity in both models of analgesia. In Tail-flick method, in doses of 100mg/kg the percentage of tail flick elongation time with allopurinol is comparable with aspirin at all time intervals with maximum activity at 60 minutes. In doses of 200mg/kg, the percentage increase in reaction time is more than aspirin at 30, 90 & 120 minutes but this difference is not statistically significant. In doses of 400mg/kg, the percent increase in reaction time is more than aspirin but the difference is not statistically significant.
In acetic acid induced writhing method, allopurinol in dose of 100mg/kg differ significantly than aspirin, latter being more effective. The analgesic activity of allopurinol in doses of 200mg/kg & 400mg/kg was comparable to aspirin.
Conclusion: Allopurinol possesses significant analgesic activity comparable with aspirin in tail flick model as well as acetic acid induced model of nociception. And this drug should be further evaluated for this indication
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