The clinical pharmacology of lisinopril

Lisinopril is an orally active, nonsulfhydryl angiotensin-converting-enzyme (ACE) inhibitor that is not metabolized or bound to protein. Peak serum concentrations occur 6-8 h after oral dosing. Lisinopril bioavailability (approximately 25%) is not significantly affected by food, age, or coadministration of hydrochlorothiazide (HCTZ), propranolol, digoxin, and glibenclamide. Lisinopril is excreted unchanged in the urine. Steady state is achieved in 2-3 days with little accumulation. Significant accumulation occurs in patients with severe renal impairment (creatinine clearance less than or equal to 30 ml/min). Lisinopril inhibits ACE activity, thereby reducing plasma angiotensin II and aldosterone and increasing plasma renin activity. Lisinopril produces a smooth, gradual blood pressure (BP) reduction in hypertensive patients without affecting heart rate or cardiovascular reflexes. The antihypertensive effect begins within 2 h, peaks around 6 h, and lasts for at least 24 h. Lisinopril produces greater systolic and diastolic BP reductions than HCTZ. Lisinopril is similar to atenolol and metoprolol in reducing diastolic BP, but superior in systolic BP reduction. Lisinopril and nifedipine produce comparable reductions in systolic and diastolic BP. When lisinopril is given once daily as monotherapy, the range of BP reductions is 11-15% in systolic and 13-17% in diastolic. HCTZ addition enhances its antihypertensive effect. Lisinopril does not produce hypokalemia, hyperglycemia, hyperuricemia, or hypercholesterolemia. Lisinopril has natriuretic properties; renal blood flow remains stable or increases. Lisinopril increases cardiac output, and decreases pulmonary capillary wedge pressure and mean arterial pressure in patients with congestive heart failure refractory to conventional treatment with digitalis and diuretics. Human experience to date (2,800 patients/subjects) indicates that lisinopril is well tolerated and has a good safety profile.