Atenolol as primary therapy in previously untreated hypertensives and as an adjuvant to other therapy. A South African Multicentre Study.

A series of 50 previously untreated hypertensives (group A) were treated with atenolol 100 mg daily and matching placebo in a double-blind cross-over study. A series of 60 hypertensives who were poorly controlled on non-beta-adrenergic receptor blocking drugs, as evidenced by a diastolic blood pressure of between 100 and 120 mmHg inclusive (group B), were treated in the same manner as group A except that they continued to take their previous non-beta-adrenergic receptor blocking drugs throughout the trial. The large majority of patients in both groups (95% and 72%) experienced a fall in blood pressure to satisfactory levels with no significant additional side-effects when compared with placebo treatment.