Name: Bepridil (Vascor)
Class: Calcium-Entry Blocking Agent (Antidysrhythmic Agent Class IV)
Mechanism: Binds to L-type Ca2+ channels ® ¯ Ca2+ in arterial smooth muscle cells ® vasodilation ® ¯ TPR, coronary blood flow, ¯ cardiac afterload. Little/no effect on venous vessels. ¯ inotropy, chronotropy, & dromotropy. Blocks cardiac Na+/K+ channel. May inhib. platelet. aggreg.
Absorption: Oral ® nearly complete absorption. 1st pass Metabolism®¯ bioavail. IV.
Dist.: Significant protein binding.
Metabolism.: Hepatic.
Excretion, t½: Long (24-50 hr.). Repeated oral dose ® t½ due to hepatic saturation. Longer t½ in elderly or pts w/hepatic cirrhosis or renal insuff.
Toxicity/S.E.s: 2° to vasodilation—dizziness, hypotension, headache, flushing, edema. Aggravation of myocardial ischemia. Drug-induced long QT syndrome (DILQT, “torsades de pointes”). C/i w/CHF, b-blockers.
Utility: Rx angina (stable, variant, unstable), supraventricular tachycardia, reentry arrhythmias, hypertension.
Special Features: