Treatment of Ventricular Ectopic Rhythms with Diphenylhydantoin

For the treatment of non-digitalis-induced ventricular ectopic rhythms, the effect of diphenylhydantoin was studied in 5 patients and compared with the effect of placebo in 5 control patients. For the first three weeks the dosage of diphenylhydantoin was 100 mg four times daily. Then, for maintenance therapy during the rest of the three-month study, the dosage was reduced to 100 mg three times daily. The numbers of premature ventricular contractions during a five-minute continuous ECG monitoring period were recorded before therapy, after three weeks of therapy, and after three months of therapy. There was a marked reduction in the number of ventricular ectopic beats in the diphenylhydantoin group compared with the control group.