The effect of low-dose spironolactone on resistant hypertension.

Our objective was to estimate the effect of addition of low-dose spironolactone to previous antihypertensive therapy in patients with resistant hypertension. Patients had 25 to 50 mg of spironolactone once daily added to the treatment of hypertension that was uncontrolled despite previous treatment with three classes of antihypertensive drugs. The effect on blood pressure was estimated by office measurements together with serum potassium and adverse effects.