A multicenter double-blind study of the efficacy and safety of once and twice daily dilevalol compared to propranolol.

Dilevalol, the R,R isomer of labetalol, is a non-selective beta-adrenergic blocking drug with vasodilator properties which differ from those of labetalol in that they are attributable to beta-2 agonism rather than alpha-1 blockade. This multicenter, double-blind, randomized study compares the antihypertensive efficacy and safety of dilevalol with propranolol and, in addition, compares the efficacy of dilevalol when given once daily with twice daily. Caucasian patients with mild and moderate essential uncomplicated hypertension were divided into three treatment groups and received either propranolol twice daily (N = 59), dilevalol twice daily (N = 60), or dilevalol once daily (N = 53). Patients were given increasing doses of these medications over a 2 to 10 week period to achieve a supine diastolic blood pressure (SuDBP) of less than 90 mm Hg. The three regimens were equally effective in lowering supine blood pressure (dilevalol daily and twice daily reduced SuDBP by 14 Hg and propranolol by 13 mm Hg). Patients with at least a 5 mm Hg reduction in SuDBP then entered a two month maintenance phase. Dilevalol, whether given once (N = 40) or twice daily (N = 55) maintained the supine systolic blood pressure more effectively (dilevalol daily--15 mm Hg, twice daily--13 mm Hg, P less than .05) than propranolol (N = 53, 11 mm Hg) and dilevalol given once daily maintained diastolic blood pressure more effectively than propranolol (17 mm Hg v 14 mm Hg, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)