Allopurinol is a drug used primarily to treat hyperuricemia (excess uric acid in blood plasma ) and its complications, including chronic gout . [ 1 ]

Allopurinol is a structural isomer of hypoxanthine (a naturally occurring purine in the body) and is an enzyme inhibitor , inhibiting xanthine oxidase . more

Allopurinol is a drug used primarily to treat hyperuricemia (excess uric acid in blood plasma ) and its complications, including chronic gout . [ 1 ]

Allopurinol is a structural isomer of hypoxanthine (a naturally occurring purine in the body) and is an enzyme inhibitor , inhibiting xanthine oxidase . [ 1 ] Xanthine oxidase is responsible for the successive oxidation of hypoxanthine and xanthine resulting in the production of uric acid , the product of human purine metabolism. [ 1 ] In addition to blocking uric acid production, inhibition of xanthine oxidase causes an increase in hypoxanthine and xanthine, which are converted to closely related purine ribotides adenosine and guanosine monophosphates. Increased levels of these ribotides causes feedback inhibition of amidophosphoribosyl transferase , the first and rate-limiting enzyme of purine biosynthesis. Allopurinol therefore decreases both uric acid formation and purine synthesis. less