What are ACE inhibitors and how do they work?

Angiotensin-converting enzyme inhibitors, or ACE inhibitors, lower blood pressure by blocking the enzyme that converts angiotensin one to angiotensin two, a potent vasoconstrictor. Without angiotensin two, blood vessels relax and blood volume decreases. Common ACE inhibitors include lisinopril, enalapril, ramipril, and captopril, all ending in the suffix "pril." They are first-line treatment for hypertension, heart failure, and diabetic nephropathy. The most distinctive side effect is a persistent dry cough caused by bradykinin accumulation, which occurs in up to 20 percent of patients.