To the Editor:—
Apropos the editorial, "Cardiac Arrhythmias and Sodium Diphenylhydantoin—An Appraisal" (201:142, 1967), I wish to draw to your attention the observation that when phenobarbital is combined with diphenylhydantoin the cardiac antiarrhythmic activity is potentiated. Although this observation was published 17 years ago,1 the combination appears not to have been evaluated by cardiologists, although traditionally used in the treatment of certain central nervous system arrhythmias.
Blachly PH. Diphenylhydantoin and Arrhythmias. JAMA. 1967;202(2):155. doi:10.1001/jama.1967.03130150123039