Pafenolol in hypertension: a double-blind randomized trial of a new beta 1-selective adrenoceptor blocker

The antihypertensive effect of pafenolol, a new beta 1-selective adrenoceptor blocker without intrinsic sympathomimetic activity and three times more selective than metoprolol, was evaluated. Twenty-three patients with essential hypertension, mean age 49 years (range 21-62), were randomized after a 4-week placebo run-in period (double-blind) to 4 weeks of either placebo, pafenolol 50 mg or 100 mg once daily. A submaximal exercise test was performed before and at the end of the treatment period. Pafenolol 50 mg and 100 mg significantly reduced recumbent and standing blood pressure compared with baseline with a mean reduction of 17/14 and 10/12 mm Hg on pafenolol 50 mg and 15/10 and 14/10 mm Hg on pafenolol 100 mg, respectively. Heart rate, both at rest and during exercise, was significantly reduced (p less than 0.05) on pafenolol 100 mg compared with placebo. The reduction in exercise heart rate (percent) was dose dependent and significantly correlated to the log plasma concentration of pafenolol (r = 0.60; p less than 0.05). It can be concluded that pafenolol had a clinically relevant antihypertensive effect when given once daily. No difference between 50 and 100 mg could be demonstrated, thus suggesting that 50 mg may be the preferred dose for antihypertensive treatment.