Hemodynamic effects of acebutolol and propranolol in hypertensive patients during exercise

Acebutolol 400 mg vs. propranolol retard 160 mg were investigated in a multicentral, double-blind, cross-over study for their action on blood pressure and heart rate in outpatients during ergometer exercise. A 2-week single-blind placebo control phase, which served as a wash-out and to eliminate placebo responders, preceded the 6-week treatment phase with propranolol (or acebutolol) followed by a further 6-week phase with acebutolol (or propranolol). At the end of each treatment phase a bicycle ergometer test was carried out, the values for 18 patients (from 26 completed investigations) were carried forward to the evaluation of the ergometry. The treatment groups were shown to be comparable. Acebutolol and propranolol produced a similar fall in systolic and diastolic blood pressure and heart rate at rest. During ergometer exercise, acebutolol led to a significantly lower increase in both systolic and diastolic blood pressure and heart rate than propranolol. The possible role of the intrinsic sympathomimetic activity (ISA) and the relative cardioselectivity of the test agents and the clinical impact of the hemodynamic findings with respect to morbidity and mortality are briefly discussed. Questioning at the end of the study revealed that significantly more patients preferred the treatment with acebutolol.