Double-blind, randomized, cross-over clinical trial of metoprolol and propranolol in mild to moderate essential hypertension.

Thirty-two patients with mild to moderate essential hypertension completed this double-blind cross-over clinical trial of propranolol and metoprolol. Metoprolol was found to be as effective and safe as propranolol in lowering the systolic and diastolic blood pressure in both supine and standing positions. The mean fall in blood pressure was greater in the group which received metoprolol as the first treatment, as compared to the group which received propranolol as the first treatment. The side-effects produced by both drugs were mild and did not require discontinuation of therapy except for 2 patients who were on metoprolol. One patient who was controlled diabetic developed severe weakness and the other patient developed bronchospasm. Metoprolol did not produce any central nervous system related side-effects.