[Therapeutic efficacy of slow-release allopurinol in gout and hyperuricaemia (author's transl)].

The efficacy of a retard preparation of allopurinol is verified by biochemical, pharmacological and clinical investigations. The action of a 300 mg allopurinol tablet, with normal release and absorption parameters, is based on the specific activity of oxypurinol, a metabolite which is formed from allopurinol according to a biotransformation process. The inhibitory action of oxypurinol on xanthine oxidase amounts to only 1/5th of that of allopurinol. On the other hand allopurinol shows an extremely short half life, so that a slow-release preparation of allopurinol seems the better way of administration to get adequate uricostatic efficacy by a single dose over a 24-hour period.