Lisinopril is an ACE inhibitor. ACE inhibitors are antihypertensive drugs that act as vasodilators and reduce peripheral resistance. They inhibit angiotensin-converting enzyme (ACE), which is involved in the conversion of angiotensin I to angiotensin II. Angiotensin II stimulates the synthesis and secretion of aldosterone and raises blood pressure via a potent direct vasoconstrictor effect. ACE is identical to bradykininase (kininase II) and ACE inhibitors also reduce the degradation of bradykinin, which is a direct vasodilator and is also involved in the generation of prostaglandins. The pharmacological actions of ACE inhibitors are thought to be primarily due to the inhibition of the renin-angiotensin-aldosterone system, but since they also effectively reduce blood pressure in patients with low renin concentrations other mechanisms are probably also involved.
Lisinopril is slowly and incompletely absorbed following oral administration. About 25% of a given dose is absorbed on average, but the absorption varies considerably between individuals, ranging from about 6 to 60%. It is already an active diacid and does not need to be metabolised in vivo. Peak concentrations in plasma are reported to occur after about 7 hours. Lisinopril is reported not to be significantly bound to plasma proteins. It is excreted unchanged in the urine. The effective half-life for accumulation following multiple doses is 12 hours in patients with normal renal function. Lisinopril is removed by haemodialysis.
Lisace® is used in the treatment of hypertension and heart failure, prophylactically after myocardial infarction and in diabetic nephropathy.