Efficacy and safety of bisoprolol and atenolol in patients with mild to moderate hypertension: a double-blind, parallel group international multicentre study.

Three hundred and fifteen patients were randomly allocated to treatment for six months with bisoprolol 5 or 10 mg day-1 or atenolol, 50 mg day-1, in a double-blind, double-dummy parallel group, international multicentre study. Two hundred and ninety-two (175 men and 117 women) were eligible for statistical follow-up. Their mean age was 52.6 years (range 28-70). All patients had a supine diastolic blood pressure of 95-120 mmHg on two occasions during the four weeks of placebo treatment. Twenty-four patients ended the study prematurely and a further 19 had their regimes changed because of an insufficient effect. The reasons for drop-out were similar in the three treatment groups. Thus, 249 patients continued to receive the treatment they were allocated to, with 80, 83 and 86 patients in the three respective groups. The sex and age distributions and the number of previously treated hypertensives were similar in the three groups. At the end of placebo treatment the supine blood pressures in the three groups (bisoprolol 5 or 10 mg day-1 or atenolol 50 mg day-1, respectively) were 163.9/102.5, 157.4/101.8 and 160.0/102.2 mmHg, respectively. The systolic blood pressure was higher (P less than 0.05) in the group receiving bisoprolol 5 mg day-1 than in the 10 mg day-1 group. After 26 weeks of treatment the supine blood pressures in the three groups were 150.6/90.8, 142.0/89.1 and 148.6/91.7 mmHg, respectively. The largest estimated difference in blood pressure reduction was 4.6/2.3 mmHg between the group receiving bisoprolol 10 mg day-1 and the group receiving atenolol 50 mg day-1. A reduction in mean blood pressure of greater than or equal to 10 mmHg was noted in 66% of the patients in the bisoprolol group (10 mg day-1), in the other groups 66 and 59%, n.s. Bisoprolol is effective, well-tolerated and safe in the treatment of hypertension. A daily dose of 5 mg seems recommendable for the majority of hypertensive patients and seems equipotent with 50 mg day-1 of atenolol in the present study.