Carvedilol, an antihypertensive agent with beta-blocking and vasodilating pro-perties, has been demonstrated to be effective in reducing blood pressure. The purpose of this study is to compare the antihypertensive efficacy, safety and tolerability of carvedilol and atenolol in patients with stage 1 to 2 essential hypertension.

In this double-blind, double-dummy, randomized, parallel study, the efficacy, safety and tolerability of once-daily carvedilol versus once-daily atenolol were evaluated in 58 patients for 8 weeks with stage 1-2 hypertension. If mean peak sitting diastolic blood pressure was equal to or greater than 90mmHg after a 4 week treatment period, the dosage for both study drugs were doubled until the end of study.

Data from 58 of 73 patients who completed the study were eligible for per-protocol analysis. At 4 weeks post treatment commencement, mean reductions in peak sitting diastolic blood pressure were 13.9mmHg (95% confidence interval 17.1-11.4) with 25mg carvedilol and 13.6mmHg (95% confidence interval 16.8-10.3) with 50mg atenolol. After the 8 week treatment period with dose titration, mean reductions in peak sitting diastolic blood pressure were 14.7mmHg (95% confidence interval 17.8-11.6) with 50mg carvedilol and 13.6mmHg (95% confidence interval 17.3-9.9) with 100mg atenolol. There were no statistically significant differences between the two treatments in the percentage of patients achieving a normalized blood pressure or in the degree of change in mean peak sitting diastolic blood pressure. Safety profiles were similar between treatments. One patient withdrew due to severe bradycardia development during the second week of treatment with atenolol.

In patients with mild to moderate hypertension, there were no significant differences between the efficacy of carvedilol or atenolol with regard to antihypertensive effect. Both carvedilol and atenolol were well tolerated with similar safety profiles.