Spironolactone and Doxazosin Treatment in Patients With Resistant Hypertension

Introduction and objectives. The aim of this study was to evaluate the use of spironolactone and doxazosin as treatment for patients with resistant hypertension. Methods. This retrospective study involved 181 outpatients with resistant hypertension (defined as a failure of blood pressure [BP] control despite treatment with three drugs, one of which was a diuretic) who received additional spironolactone (n=88) or doxazosin (n=93). Results. Mean systolic BP in the spironolactone group fell by 28 mmHg (95% confidence interval [CI], 24-32 mmHg; P<.001) and mean diastolic BP fell by 12 mmHg (95% CI, 9-14 mmHg; P<.001). The corresponding falls in the doxazosin group were 16 mmHg (95% CI, 1320 mmHg; P<.001) and 7 mmHg (95% CI, 5-9 mmHg; P<.001), respectively. The decrease was significantly greater with spironolactone for both systolic (P<.001) and diastolic (P=.003) pressures. At the end of follow-up, 30% of all patients had achieved BP control, with control being more frequent with spironolactone (39%) than doxazosin (23%; P=.02). Multivariate logistic regression analysis showed that the only factors that significantly influenced the achievement of BP control were diabetes (odds ratio=0.17; 95% CI, 0.08-0.39; P<.001) and baseline systolic BP <165 mmHg (odds ratio=2.56; 95% CI, 1.11-5.90; P=.03). Conclusions. In patients with resistant hypertension, the addition of either spironolactone or doxazosin resulted in a significant decrease in BP, though the decrease appeared to be greater with spironolactone. The presence of diabetes complicated BP control.