Comparative efficacy of perindopril and enalapril once daily using 24-hour ambulatory blood pressure monitoring

ACE inhibitors are important therapeutic agents in controlling hypertension, correcting some of its pathophysiological derangement and improving its prognosis. While there are many such agents, there may be some important differences between them. This placebo run-in, double blind, crossover study, using 24-hour ambulatory blood pressure monitoring, compares the efficacy of perindopril 4-8 mg and enalapril 10-20 mg as once daily antihypertensive agents on 32 patients. For diastolic blood pressure (DBP), perindopril had a placebo-corrected peak (P) reduction of blood pressure (BP) of -6.4 +/- 1.3 mmHg vs its placebo-corrected trough (T) of -5.2 +/- 1.7 mmHg. Enalapril had a reduction in DBP of -8.5 +/- 1.3 mmHg (P) and -5.7 +/- 1.7 mmHg (T). For systolic blood pressure (SBP), perindopril had a reduction of -7.5 +/- 1.6 mmHg (P) vs -7.3 +/- 2.2 mmHg (T) compared to enalapril with -10.8 +/- 1.6 mmHg (P) vs -8.3 +/- 2.3 mmHg (T). Placebo-corrected trough-to-peak ratio (SBP/DBP) for perindopril was 0.97/0.81 vs 0.77/0.67 for enalapril. There was no difference noted in 24-hour mean BP, area under the curve or post-dose casual BP measurements. Both perindopril and enalapril were well tolerated and the two treatment groups had similar safety profiles. Perindopril thus had a predictable and sustained blood pressure effect giving a 24-hour cover for the patient without excessive peak effect or poor trough effect.