Pafenolol is a P-glycoprotein modulator with a Ki value of 5.5 µM. pafenolol is an orally available and selective beta-adrenergic receptor antagonist.

Pafenolol (50 mg or 100 mg; once daily; patients with essential hypertension). 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.[1]