315-30-0 Wholesaler Allopurinol Factory CAS NO.315-30-0

Allopurinol does not reduce serum uric acid levels by increasing renal uric acid excretion; instead it lowers plasma urate levels by inhibiting the final steps in uric acid biosynthesis.
Uric acid in humans is formed primarily by xanthine oxidase-catalyzed oxidation of hypoxanthine and xanthine to uric acid. Allopurinol (8) and its primary metabolite, alloxanthine (9) [CAS: 2465-59-0], are inhibitors of xanthine oxidase. Inhibition of the last two steps in uric acid biosynthesis by blocking xanthine oxidase reduces the plasma concentration and urinary excretion of uric acid and increases the plasma levels and renal excretion of the more soluble oxypurine precursors. Normally, in humans the urinary purine content is almost solely uric acid; treatment with allopurinol results in the urinary excretion of hypoxanthine, xanthine, and uric acid, each with its independent solubility. Lowering the uric acid concentration in plasma below its limit of solubility facilitates the dissolution of uric acid deposits. The effectiveness of allopurinol in the treatment of gout and hyperuricemia that results from hematogical disorders and antineoplastic therapy has been demonstrated

Allopurinol is especially indicated in the treatment of chronic tophaceous gout, since patients receiving it show a pronounced decrease in their serum and urinary uric acid levels. Because it does not depend on renal mechanisms for its efficacy, allopurinol is particularly beneficial for patients who already have developed renal uric acid stones, patients with excessively high urate excretion (e.g., above 1,200 mg in 24 hours), patients with a variety of blood disorders (e.g., leukemia, polycythemia vera), patients with excessive tophus deposition, and patients who fail to respond well to the uricosuric drugs.
Allopurinol also inhibits reperfusion injury. This injury occurs when organs that either have been transplanted or have had their usual blood perfusion blocked are reperfused with blood or an appropriate buffer solution. The cause of this injury is local formation of free radicals, such as the superoxide anion, the hydroxyl free radical, or peroxynitrite. These substances are strong oxidants and are quite damaging to tissues.