COMBINATION TREATMENT WITH SUSTAINED-RELEASE VERAPAMIL AND INDAPAMIDE IN THE TREATMENT OF MILD-TO-MODERATE HYPERTENSION

Abstract

A multicenter study of the treatment of mild and moderate hypertension compared three once-daily regimens for efficacy and safety: Group I, verapamil sustained release (SR) 240 mg; Group II, verapamil SR 480 mg; and Group III, verapamil SR 240 mg plus indapamide 2.5 mg. After a 3-week placebo washout period and a 2-week preliminary treatment period with verapamil SR 240 mg, patients with sitting diastolic blood pressures of 95–115 mm Hg were randomized in a double-blind fashion to one of the three treatment groups for a duration of 16 weeks. (Patients with diastolic BP < 95 mm Hg on this initial treatment were excluded from further study.) Efficacy assessed after 16 weeks or at the end point showed all three treatments significantly reduced sitting diastolic blood pressure from baseline levels. Compared with Group I (low-dose) verapamil SR treatment, there was a reduction in Group III combination therapy of 8.6 mm Hg systolic and 3.0 mm Hg diastolic and a significant reduction in Group II high-dose verapamil SR therapy of 7.6 mm Hg systolic and 3.9 mm Hg diastolic BP. Efficacy results were independent of age or body weight. Patients who were poor responders to lead-in verapamil SR 240 mg daily prior to randomization tended to have a greater response to combination therapy than to high-dose verapamil SR. Adverse experiences leading to withdrawal from the study occurred in 21% of patients receiving high-dose verapamil (Group II), exceeding the withdrawal from the other two treatment groups (8.5% from Group III and 4% from Group I). The most frequent adverse experiences in Group II were constipation and peripheral edema; headache was most common in Groups I and III. This trial demonstrates that adding indapamide to low-dose verapamil SR enhances efficacy and is well tolerated.