A dose-response study of atenolol in mild to moderate hypertension in general practice.

A double-blind, crossover, multicentre study of 98 previously untreated patients with mild to moderate essential hypertension was carried out in general practice to assess the effect of 50 mg, 100 mg, and 200 mg atenolol, given once daily, compared with that of placebo over a period of 4 weeks each. At the end of the double-blind phase, all patients took 100 mg atenolol daily for a further 8 weeks. All three doses of atenolol produced statistically significant falls in systolic and diastolic pressure and pulse rate (p less than 0.001). The lowest pressures were achieved with 100 mg daily; a difference of 22/15 mmHg at the end of the double-bling phase, and a difference of 25/16 mmHg at the final observation. Body weight, blood urea, blood uric acid, and serum electrolytes remained within normal limits throughout the study. The incidence of side-effects with 50 mg and 100 mg atenolol was not significantly different from that caused by placebo, but the incidence of tiredness at the 200 mg dose level was greater than that caused by placebo and by the lower doses. The incidence of possible side-effects elicited by a questionnaire was low, the greatest number being volunteered by patients taking placebo. It is concluded that the optimal dose of atenolol for treating patients with mild to moderate hypertension in general practice is 100 mg daily.