Metoprolol and propranolol in the treatment of essential hypertension - a long-term comparative study

After a two-week run-in period on placebo, fifty-two patients with benign essential hypertension (WHO classes I or II) were treated with individually titrated doses of metoprolol or propranolol for 36 weeks. If blood pressure was not satisfactorily controlled by beta-blockers, a saluretic diuretic and, if necessary, hydralazine were added. Five patients on metoprolol and four on propranolol received such additional therapy. Fifty patients completed the trial. The final mean daily doses of metoprolol and propranolol were 327 mg and 282 mg, respectively. As the beta1-adrenoceptor-blocker potency of the drugs is 4:5 (i.e. 50 mg metoprolol corresponds to 40 mg propranolol in reducing exercise-induced tachycardia) the relative dose of metoprolol seemed to be slightly lower than that of propranolol. Compared to the values during the placebo period, heart rate, systolic and diastolic blood pressure in both the supine and standing position were significantly reduced in both groups after 12, 24 and 36 weeks' treatment with active drug. At the end of the treatment period, the mean reductions in supine blood pressure were 26/15 and 16/9 mm Hg in the metoprolol and propranolol groups, respectively. The reductions in supine diastolic and standing systolic blood pressures were significantly greater in the metoprolol than the propranolol group at this time.