3H-Imidazo[4,5-c]pyridine-4-carboxylic acid, 5-acetyl-4,5,6,7-tetrahydro-2-propyl-3-[[2'-(2H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl]-, [[(1-ethylpropoxy)carbonyl]oxy]methyl ester, hydrochloride (1:1)

TA-606, also known as TA-606 free, is an angiotensin type 1 receptor antagonist potentially for the treatment of hypertension. TA-606 was immediately converted to its active form, 606A, after oral administration, and it demonstrated potent inhibition of the Ang II-induced pressor response in conscious normotensive dogs. It also had a potent hypotensive effect in conscious 2K,1C-renal hypertensive dogs. These effects of TA-606 were 32 and 30 times more potent than those of losartan, respectively. In addition, EXP3174, an active metabolite of losartan, but not 606A showed an orthostatic hypotensive effect in the rat tilting model.