Antihypertensive activity of alpha-methyldopa on a twice daily regimen in comparison to metoprolol. A multi-centre controlled clinical trial.

1. The antihypertensive effects of alpha-methyldopa and metoprolol have been compared in 110 patients (fifty-one males and fifty-nine females) with previously untreated essential hypertension (sixty-eight WHO stage 1 and forty-two WHO stage 2). 2. After 2 weeks of placebo, the patients were randomly allocated to treatment with either of the two drugs: alpha-methyldopa up to 500 mg b.i.d. and metroprolol up to 200 mg b.i.d. for 6 weeks. Periodical clinical, biochemical, haematological, radiological and electrocardiographical measurements were performed. 3. The average reduction in blood pressure produced by the two drugs was comparable. 4. In general, side-effects were few and tolerable: mainly bradycardia in the metoprolol group and dizziness and drowsiness in the alpha-methyldopa group. 5. The plasma renin activity was significantly reduced in the metoprolol but not in the alpha-methyldopa group.