Clinical and haemodynamic study of atenolol (Tenormin) in essential hypertension.

1. The beta1-adrenoreceptor-blocking agent atenolol was studied in the treatment of twelve out-patients with essential hypertension. 2. With a mean dose of 110 mg of atenolol daily (range 75-200 mg/day) we observed a pronounced decrease in blood pressure. 3. Only minimal side effects were seen. 4. Cardiac output decreased from 4-6 to 3-4 l/min during treatment. This decrease did not correlate with the decrease in blood pressure but correlated well with the changes in calculated total peripheral resistance.