Arterial hypertension resistant to therapy and requiring treatment with more then three antihypertensive drugs is common. At present there are is no standard therapy for resistant hypertension based on randomised clinical trials, neither data to guide addition of further drugs to therapy. Recently some observational and retrospective trials reported good effect of spironolactone in patients with resistant hypertension, but these data were not validated by prospective randomised clinical trials.~This is a multicentric, randomised, double blind clinical trial, which will evaluate the effect of addition of 25 mg spironolactone to current medication compared to placebo. The study will enroll patients with blood pressure over 140/90 mmHg during a clinical examination, which are using at least three antihypertensive drugs, one of them being a diuretic. Average daytime systolic and diastolic blodd pressure will be evaluated by ABPM (ambulatory blood pressure monitoring).
The purpose of this study is to evaluate the efficacy of spironolactone on lowering blood pressure when added to therapy in patients with resistant arterial hypertension.