Alpurase Mechanism of Action

Anti-gout.
Allopurinol inhibits the action of the enzyme xanthine oxidase, thus reducing the oxidation of hypoxanthine to xanthine and xanthine to uric acid. The urinary purine load normally almost entirely uric acid is thereby divided between hypoxanthine, xanthine and uric acid each with its independent solubility. This results in the reduction of uric acid concentrations in both plasma and urine ideally to such an extent that deposits of uric acid are dissolved or prevented from forming.
Pharmacokinetics: Absorption and Fate: Allopurinol is absorbed from the gastrointestinal tract after oral administration and is reported to have a plasma t_½ of about 1-3 hrs. It is converted primarily in the liver to oxypurinol (alloxanthine) with a reported t_½ of 18-30 hrs in patients with normal renal function. Allopurinol and oxypurinol are not bound to plasma proteins. Excretion is mainly through the kidney but it is slow. Oxypurinol undergoes glomerular filtration as well as tubular reabsorption.