Abstract
A double-blind controlled study was conducted in 140 patients with ventricular premature contractions to find the optimal regimen for propafenone hydrochloride in Japanese patients. Three dose levels, 300 mg/day, 450 mg/day, and 600 mg/day, were compared.
Response was assessed by the reduction in number and severity of premature contractions. The rate of the response was 24 % at 300 mg/day, 56% at 450 mg/day, and 63% at 600 mg/day. The two higher dose levels were significantly better than the lowest dose of 300 mg/day.
Side effects were reported from 8 patients (17%) who received 300 mg/day, 2 (4%) at 450 mg/day, and 14 (30%) at 600 mg/day. The incidence was low at all doses, but it was significantly lower at 450 mg/day than at the two other dose levels. Conduction disturbance was related to 600 mg/day in some patients.
The clinical value of the drug was assessed, considering both the response of ventricular premature contractions and the incidence of adverse reactions. The drug was valuable or better in 24% of the patients who received 300 mg/day, 52% at 450 mg/day, and 56 % at 600 mg/day. The two higher dose levels were significantly better than the lowest dose of 300 mg/day. In conclusion, propafenone hydrochloride was shown to be effective in Japanese patients with ventricular premature contractions. Data on response and safety suggest an optimal dose of 450 mg/day.
