Posicor was removed from the market in 1998 based on case and spontaneous reports of serious interactions with other drugs. As stated by the FDA the prescribing information needed for Posicor and the seriousness of the side effects would be too complex to adequately address on the drug label. The FDA and the company agreed that it would be difficult to administer Posicor safely.
Posicor (mibefradil), a calcium channel blocker, will be available in 50 mg and 100 mg tablets for treatment of chronic stable angina pectoris and hypertension. Posicor is approved for use by itself or in combination with other antihypertensive or anti-anginal agents.
Posicor is contraindicated for use with astemizole, terfenadine and cisapride because it is metabolized by the cytochrome P450 2D6 isoenzyme. It can be life-threatening when used in conjunction with agents metabolized by P450.
Mibefradil, a subtype calcium channel blocker, blocks both low and high voltage calcium channels with greater selectivity for low voltage or Type T channels. While decreasing blood pressure, Posicor doesn’t lessen heart contractions, unlike beta blockers.