Comparison of intravenous dilevalol with placebo in moderate hypertension.

Dilevalol, an agent that combines nonselective beta-blocking and beta 2-mediated vasodilating properties, was compared with placebo in 16 subjects with moderate hypertension in a double-blind crossover study. Dilevalol or a placebo was administered intravenously in bolus injections of 25, 50, and 50 mg at 15-minute intervals. Fifteen minutes after a cumulative dose of 125 mg, the blood pressure was lowered by 11/9 mm Hg, compared with 2/1 mm Hg after placebo (p less than 0.01 between groups for systolic and diastolic blood pressure), an effect that persisted for at least 105 minutes. Standing systolic blood pressure was also lowered in dilevalol-treated patients without orthostatic symptoms. No significant effects on heart rate were noted. Fifteen minutes after the last dose of dilevalol, plasma norepinephrine levels increased from a baseline of 200 +/- 24 to 495 +/- 44 pg/ml (p less than 0.01), compared with a nonsignificant rise from 262 +/- 21 to 306 +/- 28 pg/ml with placebo vehicle. Dilevalol also increased alpha-human atrial natriuretic factor by 5.4 pg/ml, compared with 0.5 pg/ml after placebo (p less than 0.01 between groups). Plasma renin activity and plasma epinephrine, aldosterone, and cyclic guanosine monophosphate levels were unchanged by dilevalol. There were no significant adverse effects with dilevalol administration. Compared with placebo, dilevalol given intravenously appears to be safe and effective antihypertensive treatment.