Comparative study of metoprolol and alpha-methyldopa in untreated essential hypertension.

The hypotensive actions of metoprolol and alpha-methyldopa have been compared in 37 men with previously untreated essential hypertension; 36 belonged to stage 1 and 1 to stage 2 of the WHO classification. After four weeks of placebo treatment the patients were randomly allocated to treatment with either of the two drugs. Treatment was started with metoprolol 75 mg daily or alpha-methyldopa 375 mg and was doubled after eight weeks. Satisfactory blood pressure control was defined as systolic blood pressure below 160 mm Hg and diastolic below 95 mm Hg. The patients were examined every four weeks and in those with unsatisfactory control the dose was gradually increased up to a maximum daily dose of metoprolol 450 mg or alpha-methyldopa 2250 mg. The trial lasted for 24 weeks after randomization. Five patients dropped out of the study. After six months, satisfactory blood pressure control was recorded in 16 out of 17 patients and 14 out of 15 patients treated with metoprolol and alpha-methyldopa, respectively. The average reduction in blood pressure produced by the two drugs was comparable. One patient in the alpha-methyldopa group developed drug exanthema and two patients a positive Coombs' test. Other side effects were few and did not differ between the two compounds.