A comparative study of atenolol and metoprolol in the treatment of hypertension.

1 In an open, randomized cross-over investigation of thirteen patients (nine and four women, aged 37-67 years) with mild or moderate essential hypertension a comparison between atenolol and metoprolol was carried out in order to study the effects of 50, 100 and 200 mg given once daily on blood pressure and heart rate at rest and during exercise. 2 Before one beta-adrenoceptor blocking drug was replaced by the other in a patient an intervening drug-free interval of sufficient length was secured to allow an increase in the blood pressure to pretreatment levels. 3 A maximal fall in blood pressure was achieve with 50 mg atenolol once daily, with no further reduction when the dose was increased to 100 mg or 200 mg. Maximal blood pressure reduction was achieved with 100 mg metoprolol daily, while the hypertensive effect of 50 mg once daily was not consistent. Significant reductions in heart rate in all test situations were observed with 50 mg atenolol, while 200 mg metoprolol 100 was necessary to reduce exercise-induced tachycardia. 4 Atenolol 50 mg and metoprolol 100 mg once daily are efficient in treating mild or moderate hypertension and doses beyond these may not reduce the blood pressure further. On the contrary lower doses than generally recommended may be effective in the individual patient.