A xanthine oxidase inhibitor that decreases uric acid production. It also acts as an antimetabolite on some simpler organisms. Allopurinol is considered a standard treatment of hyperuricemia associated with gout. In August 2017, an oral combination agent Duzallo was approved by FDA as a dual-mechanism treatment of hyperuricemia in patients with uncontrolled gout. Duzallo contains allopurinol and [DB11560], a recently FDA-approved URAT1 inhibitor indicated for the treatment of hyperuricemia associated with gout.

LD₅₀=214 mg/kg (in mice)

For the treatment of hyperuricemia associated with primary or secondary gout. Also indicated for the treatment of primary or secondary uric acid nephropathy, with or without the symptoms of gout, as well as chemotherapy-induced hyperuricemia and recurrent renal calculi.