Single dose administration of propranolol in hypertension: a comparison of two formulations using clinic and home blood pressure measurements.

The effect of once daily conventional or long acting propranolol on blood pressure was examined in a double-blind crossover trial in 15 patients with moderate hypertension previously responsive to beta-blocking drugs. After a washout period, patients were randomly allocated to receive either conventional or long acting propranolol (160 or 320 mg once daily) and matching placebo for four weeks. Each treatment period was followed by two weeks during which only placebo was given. Clinic and home blood pressure measurements, taken 24 hours after dosing, indicated adequate and similar control during the two treatment periods. The onset of the antihypertensive action was of similar duration and no "rebound" effect was observed after withdrawing treatment. There was a similar reduction in exercise tachycardia 24 hours after dosing. No difference in the incidence of side effects was detected. These results demonstrate satisfactory blood pressure control with propranolol administered once daily, but do not support any therapeutic advantage of long acting over the conventional formulation of the drug.