3519 Allopurinol Allopurinol is only found in individuals that have used or taken this drug. It is a xanthine oxidase inhibitor that decreases uric acid production. It also acts as an antimetabolite on some simpler organisms. [PubChem] Allopurinol and its active metabolite, oxypurinol, inhibits the enzyme xanthine oxidase, blocking the conversion of the oxypurines hypoxanthine and xanthine to uric acid. Elevated concentrations of oxypurine and oxypurine inhibition of xanthine oxidase through negative feedback results in a decrease in the concentrations of uric acid in the serum and urine. Allopurinol also facilitates the incorporation of hypoxanthine and xanthine into DNA and RNA, leading to a feedback inhibition of de novo purin synthesis and a decrease in serum uric acid concentrations as a result of an increase in nucleotide concentration. 315-30-0 2094 C5H4N4O 136.038510 White powder. 350°C 569 mg/L (at 25°C) Approximately 80-90% absorbed from the gastrointestinal tract. Allopurinol inhibits the enzyme xanthine oxidase, blocking the conversion of the oxypurines hypoxanthine and xanthine to uric acid. Elevated concentrations of oxypurine and oxypurine inhibition of xanthine oxidase through negative feedback results in a decrease in the concentrations of uric acid in the blood and urine. Allopurinol also facilitates the incorporation of hypoxanthine and xanthine into DNA and RNA, resulting in further reductions of serum uric acid concentrations. Hepatic Route of Elimination: Approximately 20% of the ingested allopurinol is excreted in the feces. Half Life: 1-3 hours LD₅₀=214 mg/kg (in mice) No indication of carcinogenicity to humans (not listed by IARC). 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. LD₅₀=214 mg/kg (in mice) 2009-07-30T17:58:37Z 2026-03-26T18:39:00Z Allopurinol 40279 CPD-9024 Allopurinol DB00437 true O=C1N=CN=C2NNC=C12 C5H4N4O InChI=1S/C5H4N4O/c10-5-3-1-8-9-4(3)6-2-7-5/h1-2H,(H2,6,7,8,9,10) OFCNXPDARWKPPY-UHFFFAOYSA-N 136.1115 136.03851077 Exogenous Solid -0.55 HMDB14581 CHEMBL1467 2010 <p>Druey, J. and Schmidt, P.; US. Patent 2868,803; January 13,1959; assigned to Ciba Pharmaceutical Products Inc.<br /> Hitchings, G.H. and Falco, EA.; U.S. Patent 3,474,098; October 21,1969; assigned to Bur-<br /> roughs Wellcome &amp; Co.<br /> Cresswell, R.M.and Mentha, J.W.; US.Patent4,146,713; March27,1979; assigned to Bur-<br /> roughs Wellcome &amp; Co.</p> CHEM002503 DTXSID4022573 NS00000618 1H,2H,4H-pyrazolo[3,4-d]pyrimidin-4-one