Efficacy and safety of verapamil SR 240 mg in essential hypertension: results of a multicentric phase IV study.

In an open multicenter trial (uncontrolled study) in 4,247 patients (49.1% male, 50.9% female; aged 17-89 years) with mild, moderate, or severe hypertension, the antihypertensive efficacy and in particular the tolerability of verapamil slow-release (SR) 240 mg (Isoptin RR) were studied. The dosage of the drug was adjusted to the therapeutic response; in 88.7% of the patients it was titrated according to the study protocol: 63.2% received constantly one SR tablet throughout the 6-week treatment period; in 15.6% the dosage was increased to one and a half tablet after 2 weeks, and in 9.9% to one tablet b.i.d. after a further 2 weeks. Monotherapy with verapamil SR 240 mg normalized diastolic blood pressure (less than or equal to 90 mm Hg) in 90% of the patients with mild hypertension, 77% of those with moderate, and 61% of those with severe hypertension. It was evident that blood pressure reduction was more pronounced the higher the baseline value. Cardiac and extracardiac tolerability of verapamil SR 240 mg was good. Mean heart rate was slightly reduced, none of the patients developed a second- or third-degree atrioventricular block. Side effects were reported by 480 of the 4,247 patients (11.3%). As expected, constipation (4.03%) was the predominant adverse reaction, followed by dizziness (3.65%), headache (1.54%), and other (less than 1%). In 217 patients (5.1%) therapy was discontinued prematurely, in 139 (3.27%) because of side effects.