Once-daily penbutolol or atenolol can replace combination therapy in essential hypertension

Antihypertensive therapy was stopped in twenty-one patients with moderate hypertension. Almost all of them had been on combination therapy, usually propranolol or metoprolol with chlorthalidone, for more than a year. After a placebo 'wash-out' period of 4 weeks patients were randomly allocated in a controlled trial to a fixed daily dose of either 100 mg atenolol or 40 mg penbutolol for 6 weeks. Single-agent therapy at these doses successfully controlled the blood pressure in nineteen of the twenty-one patients, including six previously inadequately controlled on a combination. Although no conclusions can be drawn about the long-term benefits, in the patient population under study either penbutolol or atenolol given at a standard dose should provide good initial blood pressure control in most patients with mild to moderate hypertension.