Allopurinol is a drug used in treatment of gout (A painful inflammation of the big toe and foot) and other conditions related with high level of uric acid in the body like kidney disease, cancer and treatment with diuretics. The drug works by inhibiting the enzyme xanthine oxidase that plays a role in converting hypoxanthine to xanthine and uric acid. Allopurinol thus reduces the production of uric acid and alleviates all symptoms associated with high uric acid level.