Drug interactions with ACE inhibitors.

Drug interactions common to all angiotensin-converting enzyme (ACE) inhibitors include those with thiazide diuretics and other antihypertensive agents. Interactions involving specific ACE inhibitors include captopril-digoxin, resulting in decreased clearance of digoxin from plasma in patients with heart failure, and captopril-probenecid, causing a decrease in captopril clearance. Tissue kinins, such as bradykinin, are metabolised by ACE inhibitors. Interactions involving bradykinin include captopril-indomethacin, in which an attenuation of the antihypertensive effects of captopril is manifest. Interestingly, neither enalapril nor lisinopril appear to show this interaction with indomethacin. Kinin-based interactions may also be important in the genesis of ACE inhibitor-induced cough and skin rash. Renal dysfunction affects the pharmacokinetics and pharmacodynamics of all ACE inhibitors, necessitating dosage reduction. Hepatic impairment is of less clinical importance, causing a delay in the onset of action of enalapril with initial doses, but probably having little relevance to long-term therapy.