Establishment of specific indications for new drugs not infrequently occurs in distinct stages. Initial enthusiasm may be prompted by preliminary reports which indicate that a new agent offers unique pharmacologic advantages. These euphoric estimates are soon tempered by descriptions of untoward or ineffectual responses. Finally, after observations upon larger series of patients are obtained, unhurried reflection permits a balanced estimate of the precise role which the drug fulfills. These phases of clinical acceptance may be clearly identified in the responses in the past decade to the antiarrhythmic agent, diphenylhydantoin (Dilantin).
Certain effects of diphenylhydantoin upon the heart were documented as early as 1938, four years after the introduction of this drug for the treatment of epilepsy. In 1958, Leonard described the successful clinical application of diphenylhydantoin in the treatment of ventricular tachycardia.1 Numerous publications since that time have described the effectiveness of this drug in the treatment of a