Efficacy of a very-low-dose combination of perindopril and indapamide--preterax compared with cilazapril monotherapy in patients with inadequate blood pressure control--a randomized, double-blind, add-on study.

BACKGROUND Combined regimen may be superior to monotherapy in blood pressure (BP) control. Since BP control is critically related to cardiovascular mortality and morbidity in hypertensive patients, this study aimed to evaluate the efficacy and safety of a low-dose combined regimen of preterax compared with cilazapril monotherapy for better BP control in treated hypertensive patients. METHODS Stable hypertensive patients were evaluated if their systolic BP (SBP) was > 130 mmHg and/or diastolic BP (DBP) was > 85 mmHg even with up to 2 antihypertensive drugs. Patients were excluded if they were on angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers or a diuretic. They were then randomized to receive either preterax (perindopril 2 mg and indapamide 0.625 mg) or cilazapril 2.5 mg once daily in a double-blind fashion for a period of 12 weeks after a 2-week placebo run-in phase. Sitting BP was recorded and the safety and efficacy were evaluated at each visit every 4 weeks. Response was defined as positive if SBP was < or = 140 mmHg and DBP was < or = 90 mmHg at the last visit or there was > 20 mmHg reduction in SBP and/or > 10 mmHg reduction in DBP using either treatment. Plasma biochemical analysis was performed both before and after the treatment. RESULTS Among the 47 patients initially enrolled, 41 completed the study (21 in the preterax group, 20 in the cilazapril group). There was no difference in the number of adverse events between the 2 groups. SBP was significantly reduced by preterax (13.43 +/- 12.48mmHg, p < 0.0001) and cilazapril (9.00 +/- 13.75 mmHg, p < 0.05). However, DBP was significantly reduced only by preterax (7.67 +/- 9.40 mmHg, p = 0.0009) but not by cilazapril (3.60 +/- 8.37 mmHg, p > 0.05). The response rate was significantly higher to preterax (100%) than to cilazapril (70%) (p = 0.0086). CONCLUSION Though similar in safety, combined regimen preterax was more effective than cilazapril to facilitate adequate BP control in already-treated hypertensives. It can be added on to other antihypertensives for better BP control in clinical hypertension.