Background: Hypertension is resistant to pharmacologic therapy in 5% to 10% of patients. The current study tested whether addition of spironolactone to the treatment of patients with refractory hypertension would lead to adequate blood pressure (BP) control.
Methods: Among 520 patients who were referred for treatment of hypertension to one medical clinic from 1997 to 1999, a total of 25 patients who met the inclusion criteria of refractory hypertension were prospectively included in this study. The inclusion criteria were as follows: 1) hypertension of > or = 6 months without any apparent cause; 2) clinical BP measurement and mean 24-h ambulatory BP monitoring > 140/90 mm Hg despite treatment with at least two antihypertensive drugs; 3) no prior therapy with spironolactone; and 4) no renal insufficiency. Spironolactone was added to the previous regimen at a dosage of 1 mg/kg/day while any angiotensin converting enzyme inhibitor was suppressed. Serum potassium and creatinine levels were checked before the introduction of spironolactone and 1 month later.
Results: After 1 month of therapy with spironolactone, 23 patients had a clinical BP < 140/90 mm Hg. Ambulatory BP monitoring when compared before and 1 month after initiation of spironolactone decreased significantly (systolic BP from 152 +/- 2 mm Hg to 128 +/- 2 mm Hg, P < .001; and diastolic BP from 86 +/- 2 mm Hg to 76 +/- 2 mm Hg, P < .013). By 3 months after the introduction of spironolactone, the mean number of antihypertensive drugs required per patient was significantly reduced (from 3.2 +/- 0.2 to 2.1 +/- 0.2, P < .001). No patient required discontinuation of spironolactone due to adverse renal effects.
Conclusion: Spironolactone is a safe, effective therapy for patients with refractory hypertension.