A multicenter, parallel comparative study of the antihypertensive efficacy of once-daily lisinopril vs. enalapril with 24-hour ambulatory blood pressure monitoring (ABPM) in essential hypertension.

The aim of the study was to compare the antihypertensive efficacy of once-daily lisinopril (LIS) vs. enalapril (ENAL) during both normal daily activity and sleep, in mild-to-moderate essential hypertension. After a 3 week wash-out period, 34 patients (17m, 17f) aged 22 to 67 years were randomized in a multicenter, open, parallel fashion: 17 received lisinopril 10mg and 17 enalapril 10mg. After 4 weeks dose was adjusted if needed (20mg) and continued for another 8 week period. At the end of the 3 week drug-free baseline period and during the last week of treatment, 24-h ABPM was performed using an oscillometric non-invasive automated device ACP2200. Recordings were obtained at 20 min intervals for the entire 24-h period. With no differences in initial ABPM between groups (LIS 142.3±10.4/ 91.4±5.1 vs ENAL 141.8±14.4/90±5.7 mmHg; p=ns), a significant reduction of ABPM mean values of 24-h SBP (127.8±15 vs 131.4±15 mmHg), 24-h DBP (82.5±9 vs 83.9±7.7 mmHg), SBP and DBP at early morning hours (123±13/79±9 vs 129.3±13.7/82.7±8 mmHg) of both groups was observed, with no significant differences between patients treated with LIS or ENAL. Nevertheless, the average lowering of 24-h SBP-load (−34.8±26.1% vs −15.7±17.8%; p=0.0182) and nighttime SBP-load (−23.2±26.4% vs −6.8±13.5%; p=0.0292) were significantly higher in patients treated with lisinopril. We conclude that at equipotent once-daily dose, lisinopril tends to be more efficient than enalapril in lowering blood pressure assessed by 24-h ABPM, but only the reduction of blood 24-h and nighttime systolic blood pressure load reaches statistical significance.