Instead of preventing cardiac arrest, encainide
and flecainide caused cardiac arrest.
Description: Since encainide
and flecainide were found to worsen patient survival in CAST I, in CAST II the protocol was changed to evaluate 993 post- MI patients receiving moricizine or placebo who were more likely to experience arrhythmias; the enrollment time was narrowed to 4 to 90 days post-MI, and the qualifying ejection fraction was lowered to less than or equal to 40 percent.
Schultz, deputy FDA commissioner for policy, told the Senate committee that two drugs approved to correct abnormal heart rhythms, encainide
and flecainide, subsequently were used off-label for irregular heart rhythms during a heart attack - a use that was supported by several journal articles.
CAST investigators, "Preliminary Report: Effect of Encainide
and Flecainide on Mortality in a Randomized Trial of Arrhythmia Suppression After Myocardial Infarcation," New England Journal of Medicine, 321 (1989): 406-412.
Drugs which could be affected by poor metabolism include metoprolol, a 13-blocker, and recently Encainide
, scheme 5, a potent drug which suppresses irregular heart beats and which has been examined in patients by Laganiere in collaboration with the Ottawa Heart Institute and other North American centres.
Study patients taking encainide
(marketed as Enkaid by Bristol Laboratories in Evansville, Ind.
7%; 56/730) was seen in patients treated with encainide
or flecainide (Class 1C antiarrhythmics) compared with that seen in patients assigned to placebo (3.
Increased risk of death and cardiac arrest from encainide
and flecainide in patients after non-Q-wave acute myocardial infarction in the Cardiac Arrhythmia Suppression Trial.
was provided by Bristol-Myers, Princeton, NJ.