Interactive image SMILES[show]. c1c2c([nH]n1)ncnc2O. InChI[show]. InChI=1S/C5H4N4O/c10-5-3-1-8-9-4(3)6-2-7-5/h1-2H,(H2,6,7,8,9,10) ☑ Y. Key:OFCNXPDARWKPPY-UHFFFAOYSA-N ☑ Y. (verify). Allopurinol, sold under the brand name Zyloprim among others, is a medication used to . Allopurinol is sold as an injection for...