A double-blind comparison of spironolactone and hydrochlorothiazide in hypertensive patients treated with metoprolol.

The antihypertensive effects of hydrochlorothiazide and spironolactone when added to treatment with metoprolol were compared in a double-blind trial comprising 55 previously untreated patients with essential hypertension. Twenty-four patients became normotensive on metoprolol alone, whereas ten patients were randomized to additional therapy with hydrochlorothiazide and ten to spironolactone. Eleven patients dropped out of the trial. Spironolactone was significantly more effective than hydrochlorothiazide as regards reduction of the diastolic blood pressure, Side effects were few and mild during all phases of the study.