Dilevalol: a dose-response study in normal volunteers.

Dilevalol, 100 mg, 200 mg and 400 mg, and placebo were given to eight normal volunteers and the effect on blood pressure and heart rate studied at rest and on exercise. There was a dose-dependent fall in exercising heart rate and in the increased heart rate on exercise with dilevalol, while exercising systolic blood pressure and the rise in systolic blood pressure on exercise fell dose-dependently up to 200 mg, but the effect of 400 mg was similar. Diastolic blood pressure was not affected. Supine heart rate and blood pressure changes were not different from placebo. Tilt heart rate fell most constantly from 200 mg. Some fall in tilt systolic blood pressure was seen but this was not dose-dependent, diastolic blood pressure was not affected. There was wide variation in plasma concentration of dilevalol, as might be expected from a liver metabolised drug, with a relatively larger amount absorbed of the 400 mg dose compared to the 100 or 200 mg doses.