irbesartan [ 2-n-butyl-3-((2'-(1H-tetrazol-5-yl)biphenyl-4-yl)methyl)-1,3-diazaspiro(4,4)non-1-en-4-one,Aprovel,Avapro,BMS 186295,BMS Brand of Irbesartan,BMS-186295,Bristol Myers Brand of Irbesartan,Karvea,SR 47436,SR-47436,Sanofi Winthrop Brand of Irbesartan ] a nonpeptide At(1) subtype angiotensin II receptor antagonist; structure given in first source