Mibefradil

495.62900

495.63

27B90X776A

DTXSID1023318

C - Cardiovascular system

67.45000

5.27090

1.18g/cm3

647.6ºC at 760mmHg

345.5ºC

1.585

1.17E-16mmHg at 25°C

≥ 99%, primarily to alpha 1-acid glycoprotein.

For the treatment of angina and high blood pressure.

Mibefradil belongs to a group of medicines called calcium channel blocking agents, or, more commonly, calcium channel blockers. Calcium channel blocking agents affect the movement of calcium into the cells of the heart and blood vessels. As a result, they relax blood vessels and increase the supply of blood and oxygen to the heart while reducing its workload. Mibefradil is a benzimidazoyl-substituted tetraline that selectively binds and inhibits T-type calcium channels.

Drugs and compounds which inhibit or antagonize the biosynthesis or actions of CYTOCHROME P-450 CYP1A2. (See all compounds classified as Cytochrome P-450 CYP1A2 Inhibitors.)|A class of drugs that act by selective inhibition of calcium influx through cellular membranes. (See all compounds classified as Calcium Channel Blockers.)|Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless of pharmacological mechanism. Among the antihypertensive agents are DIURETICS; (especially DIURETICS, THIAZIDE); ADRENERGIC BETA-ANTAGONISTS; ADRENERGIC ALPHA-ANTAGONISTS; ANGIOTENSIN-CONVERTING ENZYME INHIBITORS; CALCIUM CHANNEL BLOCKERS; GANGLIONIC BLOCKERS; and VASODILATOR AGENTS. (See all compounds classified as Antihypertensive Agents.)|Drugs used to cause dilation of the blood vessels. (See all compounds classified as Vasodilator Agents.)

Bioavailability after a single dose is 70%. After multiple dosing, the proportion of mibefradil undergoing first-pass metabolism is reduced, resulting in a steady state bioavailability of approximately 90%. Food does not affect the rate or extent of absorption of mibefradil.

The two metabolic pathways that mibefradil undergoes are esterase-catalyzed hydrolysis of the ester side chain (producing an alcohol metabolite) and cytochrome P450 3A4-catalyzed oxidation (that becomes less important during chronic dosing). The pharmacologic effect of the metabolite is approximately 10% of that of the parent mibefradil.

17 to 25 hours at steady state.

Mibefradil is a tetralol calcium channel blocking agent that inhibits the influx of calcium ions across both the T (low-voltage) and L (high-voltage) calcium channels of cardiac and vascular smooth muscle, with a greater selectivity for T channels. Vasodilation occurs in vascular smooth muscle, causing a decrease in peripheral vascular resistance and a resulting decrease in blood pressure. Mibefradil causes a slight increase in cardiac output during chronic dosing. Mibefradil slows sinus and atrioventricular (AV) node conduction, producing a slight reduction in heart rate and a slight increase in the PR interval. It has also been shown to slightly lengthen the corrected sinus node recovery time and AH interval and to raise the Wenckebach point. The mechanism by which mibefradil reduces angina is not known, but is thought to be attributed to a reduction in heart rate, total peripheral resistance (afterload), and the heart rate–systolic blood pressure product at any given level of exercise. The result of these effects is a decrease in cardiac workload and myocardial oxygen demand.

Mibefradil

Pharmaceuticals