Me. Mullins et al., LIFE-THREATENING INTERACTION OF MIBEFRADIL AND BETA-BLOCKERS WITH DIHYDROPYRIDINE CALCIUM-CHANNEL BLOCKERS, JAMA, the journal of the American Medical Association, 280(2), 1998, pp. 157-158
Mibefradil is a T-type and L-type calcium channel blocker (CCB) releas
ed in the United States in 1997 for management of hypertension and chr
onic stable angina. Postmarketing surveillance revealed a potential se
rious interaction between mibefradil and beta-blockers, digoxin, verap
amil, and diltiazem, especially in elderly patients. The manufacturer
voluntarily withdrew mibefradil on June 8, 1998. We describe 4 cases o
f cardiogenic shock in patients taking mibefradil and beta-blockers wh
o began taking dihydropyridine CCBs. One case resulted in death; the o
ther 3 survived episodes of cardiogenic shock with intensive support o
f heart rate and blood pressure. Physicians who are preparing to switc
h patients' medications from mibefradil to other antihypertensive agen
ts should be aware of these potentially life-threatening drug-drug int
eractions.