Allopurinol, Xanthine Oxidase, and Hyperuremic States

Allopurinol is used to lower uric acid levels in the treatment of primary gout, as a prophylaxis in myeloproliferative neoplastic disease, for investigational purposes in Lesch-Nyhan syndrome, and as an adjunct with thiazide diuretics or ethambutol (see Chapter 24). Allopurinol acts by inhibiting xanthine oxidase, which converts hypoxanthine into xanthine and in turn becomes oxidized into uric acid. 

When xanthine oxidase is inhibited by allopurinol, me plasma level of uric acid and me size of me urate pool in me body bom decrease. 

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