Objectives: A multicenter double-blind randomized parallel trial was designed to evaluate the use of an association of the calcium channel-blocker amlodipine and the angiotensin converting enzyme inhibitor enalapril as a single galenic formulation given in two differents dosages in comparison to each drug of this association given alone to patients with mild-to-moderate essential hypertension. Methods: For each treatment regimem the anti-hypertensive efficacy was evaluated through routine blood pressure recordings and ambulatory blood pressure monitoring (ABPM). It was also evaluated the tolerability, clinical and biochemical safety of the compounds, effects on glucose and lipid metabolism as well as the effects on left ventricle geometry. To evaluate with more acuracy the development of the adverse event, leg edema, the leg volume was measured through a methodology that uses the Archimeds principle. Ninety-nine patients with diastolic blood pressure ranging from 90 to 115 mm Hg after 3 weeks of washout of previous anti-hypertensive medications were included in the study and followed for 24 weeks. Results: All therapeutic regimens were considered safe and adequate for the treatment of hypertensive patients. The anti-hypertensive efficacy of the amlodipine + enalapril association given in two different dosages, evaluated through both routine blood pressure and the ABPM, was similar to that of amlodipine given alone and greater than that of enalapril, despite of the lower dosage of each compound. On the other hand, the association regimen in both dosages showed a superior tolerability profile in comparison to the therapies with amlodipine or enalapril alone. Indeed it was observed a lower incidence of cough and leg edema as well as smaller increments in leg volume in patients treated with the association. The amlodipine + enalapril association did not induce changes in the metabolic profile, but did improve the left ventricle geometry. Conclusions: The association of amlodipine and enalapril in a single galenic formulation is safe, highly effective and better tolerated then when each compound is given alone for the treatment of patients with mild-to-moderate essential hypertension.
Keywords: Essential hypertension. Anti-hypertensive drugs combination. Amlodipine. Enalapril.;