HYZAAR® 50-12.5 (losartan potassium-hydrochlorothiazide), HYZAAR® 100-12.5 (losartan potassium-hydrochlorothiazide) and HYZAAR® 100-25 (losartan potassium-hydrochlorothiazide) combine an angiotensin II receptor (type AT1) antagonist and a diuretic, hydrochlorothiazide.

COZAAR (losartan potassium) is an angiotensin II receptor (type AT1) antagonist. Losartan potassium, a non-peptide molecule, is chemically described as 2-butyl-4-chloro-1-[p-(o-1H-tetrazol-5ylphenyl)benzyl]imidazole-5-methanol monopotassium salt.