COMPARISON OF A NEW VASODILATING BETA-BLOCKER, CARVEDILOL, WITH ATENOLOL IN THE TREATMENT OF MILD-TO-MODERATE ESSENTIAL-HYPERTENSION

Carvedilol is a new cardiovascular compound with the combined pharmacologic properties of nonselective beta-blockade and vasodilation. The aim of this study was to compare the safety and antihypertensive efficacy of 25 to 50 mg carvedilol once daily with 50 to 100 mg atenolol once daily in patients with mild to moderate essential hypertension. This was a multicenter study conducted in Europe. After a single-blind placebo run-in phase, 325 eligible patients with stable hypertension were randomized to receive 25 mg carvedilol once daily (161 patients) or 50 mg atenolol (164 patients) in a double-blind 8-week treatment phase. After 4 weeks, the dosage was doubled if there was inadequate response. The primary index of efficacy (response) was the reduction of mean sitting diastolic blood pressure to 90 mg Hg or less (normalized) or by at least 10 mm Hg from baseline. At each of three to six run-in phase visits and after 2, 4, and 8 weeks of treatment, sitting blood pressure and heart rate at trough were measured in triplicate, and body weight, adverse experiences, compliance, and use of concomitant medications were assessed. Laboratory tests, including fasting serum lipids, and electrocardiograms were also monitored during the trial. After 8 weeks of treatment, response rates in the carvedilol and atenolol treatment groups were 75% and 82%, respectively. Compared to baseline, the mean sitting blood pressure was significantly (P < .05) reduced by carvedilol from 165/104 mm Hg to 147/89 mm Hg. With atenolol, mean sitting blood pressure was significantly (P < .05) reduced from 167/104 mm Hg to 150/90 mm Hg. There was no statistically significant difference between the two treatments in the percentage of patients achieving a response or a normalized blood pressure or in the degree of change in mean sitting systolic or diastolic blood pressure. Overall, adverse experiences were reported by 22% of patients who received carvedilol and by 21% of patients who received atenolol. The most common adverse experiences were headache, dizziness/vertigo, and somnolence in the carvedilol group, and dizziness and fatigue in the atenolol group. In patients with mild to moderate hypertension, there was no statistically significant difference between the efficacy of carvedilol or atenolol with regard to the degree of reduction in blood pressure or the percentage of patients achieving a response to therapy. Carvedilol and atenolol were equally effective and well-tolerated.