Mibefradil. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in the management of hypertension and angina pectoris.

Abstract

Mibefradil belongs to a new class of calcium antagonists, the tetralol derivatives. It selectively blocks T-type calcium channels in contrast to other calcium antagonists which block only L-type channels. Mibefradil relaxes coronary arteries without suppressing myocardial contractility and causes a dose-related decrease in heart rate. When given orally once daily to patients with hypertension mibefradil produces a dose-related decrease in blood pressure which is sustained for 24 hours and improves exercise performance in patients with stable angina pectoris. In patients with generally mild to moderate hypertension oral mibefradil was superior to nifedipine SR and diltiazem CD, tended to be more effective than nifedipine GITS and had similar efficacy to amlodipine. Mibefradil 50 to 100mg once daily also has antianginal and anti-ischaemic effects. The drug improves the duration of symptom-limited exercise and the time to onset of ischaemia, and reduces the frequency of anginal attacks and consumption of nitroglycerin. Its efficacy is similar to that of diltiazem and tends to be greater than that of amlodipine in patients with stable angina. Mibefradil is generally well tolerated and is associated with a lower incidence of leg oedema than amlodipine and nifedipine. Thus, mibefradil is a calcium antagonist with a predictable cardiovascular profile, which, on the basis of available clinical data, is an effective alternative to other drugs widely used in the treatment of hypertension and stable angina pectoris.