Trandolapril is a prodrug that is deesterified to trandolaprilat. It is believed to exert its antihypertensive effect through the renin–angiotensin–aldosterone system. Trandolapril has a half-life of about six hours, while trandolaprilat has a half life of about ten hours. Trandolaprilat has about eight times the activity of its parent drug. About one-third of trandolapril and its metabolites are excreted in the urine, and about two-thirds of trandolapril and its metabolites are excreted in the feces. Serum protein binding of trandolapril is about 80%.