Comparative study of alprenolol and methyldopa in previously untreated essential hypertension.

The effects of methyldopa and alprenolol were compared in I5 patients with previously untreated essential hypertension. The patients were randonly allocated to start treatment with one of the drugs. All blood pressures and side effects were registered blindly as regards type of treatment by the same observer. The study was not blind as regards the patients as non-matching tablets were used. Alprenolol (using a dosage of 400 or 8oo mg per day) was shown to be more effective than methyldopa (75o or i5oo mg per day) in lowering the resting supine and erect arterial systolic and diastolic blood pressures. During exercise (bicycle ergometer, IOO W) no statistically sigmificant difference between the two drugs could be shown. The systolic and diastolic resting supine blood pressures after three months of alprenolol treatment and one month of subsequent placebo administration were still significantly lower than the initial pressures.