A comparison of dilevalol and placebo in the management of isolated systolic hypertension using ambulatory monitoring.

1. The antihypertensive effect of dilevalol, a compound which combines beta-adrenoceptor blocking and vasodilating properties due to beta 2-adrenoceptor agonism, was studied in nineteen patients with isolated systolic hypertension (ISH). A randomized, double-blind, placebo-controlled, cross-over trial with two 4 week treatment periods was used to compare the efficacy of once daily dosing with dilevalol (in the range of 100-400 mg daily) against placebo. Assessment of response involved both casual blood pressure readings (amongst all patients) and 24 h ambulatory blood pressure monitoring (in ten of the nineteen patients). 2. A mean fall of 12/5 mm Hg (s.e. mean 3/2, P less than 0.05) and 9/3 mm Hg (s.e. mean 3/2, P less than 0.05) in supine and standing blood pressure respectively was observed with dilevalol. Mean heart rate was unchanged. The ambulatory monitoring profile demonstrated a smaller reduction in mean blood pressure (7/8 mm Hg) over the 24 h period and a reduction of 10/11 mm Hg over the daytime period. A blunting of the early morning increase in systolic pressure was observed with dilevalol. 3. The drug was well tolerated with light headedness and lethargy being reported more commonly than with placebo. Biochemical parameters were unaffected. 4. It is concluded that dilevalol in the doses used has a small but measurable antihypertensive effect as monotherapy in the treatment of ISH.