Efficacy and tolerability of a combination of enalapril and hydrochlorothiazide in the treatment of hypertension measured manually and with an ambulatory blood pressure monitor.

The efficacy and tolerability of an enalapril maleate-hydrochlorothiazide combination (EM-HCTZ) were evaluated in a prospective, open-label study in 26 patients with uncomplicated essential hypertension (mean baseline sitting systolic/diastolic blood pressure: 153/103 mmHg) requiring two agents to reduce sitting diastolic blood pressure (SDBP) below 90 mmHg. Their mean age was 52 years. Patients received enalapril 5 mg daily, which was increased to 10 mg if SDBP was not reduced to < 90 mmHg during a 5-week titration period following washout. If blood pressure did not reach that goal, 25 mg hydrochlorothiazide was added. Only patients who required enalapril 10 mg and hydrochlorothiazide 25 mg for control (SDBP < 90 mmHg) at the end of titration received open-label EM-HCTZ as maintenance therapy for 6 weeks. The SDBP of 19 of the 26 patients (73%) who began titration was controlled at the end of titration, and they received maintenance therapy. During maintenance, the mean SDBP decreased from baseline 13.2 mmHg at week 2, 13.3 mmHg at week 4, and 10.1 mmHg at week 6. All changes from baseline were significant. At the end of the maintenance period, SDBP was controlled in 8 (42%) of 19 patients enrolled. One patient was withdrawn from the study because blood pressure was poorly controlled. Ambulatory blood pressure (ABP) was monitored, average outcome was computed for each patient during the 24-hour interval, and with a paired comparison, baseline and follow-up data were compared with the data measured manually. The mean baseline ABP was 9 mmHg lower than the baseline SDBP measured manually (r = 0.58, P = 0.01). Following treatment with EM-HCTZ, mean diastolic blood pressure fell 10 mmHg and mean systolic blood pressure fell 15 mmHg. In summary, EM-HCTZ was highly effective and generally well-tolerated in a substantial proportion of participants whose SDBP remained > 90 mmHg on enalapril 10 mg. Important differences between blood pressure measured manually and with a monitor were also demonstrated.