Antihypertensive effect of prizidilol

Prizidilol (SK&F 92657), a new combined precapillary vasodilator and nonselective beta-adrenoceptor blocking drug, was given to 19 patients with essential hypertension. Following placebo (4 weeks, single-blind), patients were randomly assigned to receive either 200 or 400 mg prizidilol once daily. Blood pressure and heart rate were measured every second week for 12 weeks, 24 h after drug administration. In patients with inadequate blood pressure response the dosage was then increased to 400 mg twice daily for 4 additional weeks. In this study prizidilol given once daily did not effectively reduce systolic blood pressure for 24 h, but when given twice daily (400 mg X 2), it had an effective antihypertensive effect. Plasma concentrations of prizidilol were generally low 24 h after drug intake, and there was no significant correlation between blood pressure reduction and plasma concentration.