Atenolol and bisoprolol, two beta-1-selective blockers, were compared in patients with mild and medium severe hypertension. Forty patients with a diastolic blood pressure of 95-115 mm Hg were two weeks after discontinuation of treatment divided at random into two groups treated with 50 mg atenolol and 5 mg bisoprolol. If the blood pressure was not affected by this dosage, the dose was raised to 100 mg atenolol and 10 mg bisoprolol. The blood pressure readings, heart rate, side effects of the drugs, laboratory and echocardiographic values were followed up for a period of three months. The authors recorded a marked decline of pressure and heart rate after the first week of therapy, the pressure readings in an upright position did not differ statistically from values in a sitting position, orthostatic hypotension was not recorded. The rate of success of bisoprolol was 85%, of atenolol 75%. During treatment no serious side-effects were observed. The biochemical parameters and echocardiographic values were not altered significantly by treatment. Atenolol and bisoprolol are two effective beta-1-selective blockers with a comparable effect in the treatment of mild and medium severe hypertension. They are useful in monotherapy as well as in combination with other antihypertensive drugs. In hypertension associated with diabetes mellitus, incipient bronchopulmonary disease and pregnancy they are also indicated. They are well tolerated also by elderly patients, an advantage of bisoprolol may be that it has a smaller impact on pressure and heart rate during the night.

Keywords: Adult; Atenolol /adverse effects/; Bisoprolol /adverse effects/; Blood Pressure /drug effects/; Female; Heart Rate /drug effects/; Humans; Hypertension /drug therapy/; Male