Ramipril is an antihypertensive agent that is useful in controlling high blood pressure, which may lead to stroke or heart failure. The drug works by inhibition of angiotensin-converting enzyme (ACE) in human subjects and animals. ACE is a peptidyl dipeptidase that catalyzes the conversion of angiotensin I to the vasoconstrictor angiotensin II, which stimulates aldosterone secretion by the adrenal cortex. Inhibition of ACE results in decreased plasma angiotensin II, leading to decreased vasopressor activity and aldosterone secretion. Side effects include dizziness, coughing, fatigue, nausea, chest pain, and hypotension.