Atenolol administered once daily in primary hypertension. Effects on blood pressure in relation to pre-treatment plasma renin activity.

The antihypertensive effect on the selective beta-1-adrenoceptor blocking agent, atenolol, given in doses of 100 and 200 mg once daily, was evaluated in 37 patients with primary hypertension. The drug induced an efficient reduction of BP, and in the whole patient series there was no difference in BP on either dosage. Exercise tests, performed in 10 patients, showed the same degree of partial beta-blockade 24 hours after intake of 100 and 200 mg atenolol. PRA decreased during treatment with atenolol but there was no correlation between the stimulated pretreatment renin level and the antihypertensive effect of atenolol. Side-effects were few and 35 out of 37 patients continued on atenolol treatment. Central nervous side-effects were not seen.