Trandolapril is a prodrug that is de-esterified to trandolaprilat. it is believed to exert its antihypertensive effect through the renin-angiotensin-aldosterone system. trandolapril has a half-life of about 6 hours, and trandolaprilat has a half life of about 10 h. 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%.