Efficacy and tolerability of enalapril (20 mg)/hydrochlorothiazide (12.5 mg) combination therapy in essential hypertension.

The efficacy and tolerability of a preconstituted formulation combining enalapril (20 mg) and hydrochlorothiazide (12.5 mg) were evaluated in patients with essential hypertension unresponsive to enalapril monotherapy (20 mg/day). The duration of this open-lable, multicenter, noncomparative trial was 12 weeks: a two-week washout period followed by ten weeks of active treatment. During the active treatment period, patients received enalapril alone (up to 20 mg/day) for six weeks. At the end of week 6, patients with supine diastolic blood pressure greater than 90 mmHg were treated with the enalapril/hydrochlorothiazide combination therapy (EN/HCTZ). Of the 147 patients who were entered into the study, 81 were not normalized with enalapril alone. At the end of the study period, blood pressure was normalized (supine diastolic blood pressure less than or equal to 90 mmHg) in 60 (74%) of the 81 patients who had received the EN/HCTZ combination. Overall, 86% of the patients achieved satisfactory blood pressure control with this therapeutic regimen. Adverse reactions were mild and transient. Six patients experienced undesirable effects, the most frequent of which was coughing (2 cases). Neither enalapril (20 mg/day) alone nor the EN/HCTZ combination had any significant influence on any of the metabolic parameters evaluated. No hypokalemia and no significant changes in serum lipids occurred in the course of the study.