Dose-response effect of the lercanidipine/enalapril combination: a pooled analysis

Objective: The dose-effect relationship of fixed-dose combinations of anti-hypertensive drugs has been only poorly explored. This pooled analysis investigates the dose-response relationship of fixed-dose lercanidipine+enalapril in patients with mild-to-moderate hypertension. Research design and methods: This was an individual patient data analysis of four randomized studies (n = 2340). Main outcome measures: The primary efficacy variable was the change from baseline in sitting diastolic blood pressure (SDBP). Secondary variables were change from baseline in sitting systolic BP (SSBP), proportion of responder patients, and safety. Results: All fixed-dose combinations were superior to placebo in the reduction of SDBP. The greatest effect was observed with the market-available combination lercanidipine 20 mg/enalapril 20 mg (-15.3 mmHg vs. baseline; p < 0.05). The reduction in SDBP associated with the other two marketed fixed combinations of lercanidipine/enalapril were -10.7 mmHg for the 10 mg/20 mg combination and -9.8 mmHg for the 10 mg/10 mg combination (p < .05 for both comparisons). Similar findings were reported for SSBP reduction: the greatest effect was observed with lercanidipine 20 mg/enalapril 20 mg (-19.2mmHg). The reduction in SSBP was-12.5mmHg for the 10 mg/20 mg combination and -11.1 mmHg for the 10 mg/10 mg combination (p < .05 for all comparisons). The highest responder rate was reported with lercanidipine 20 mg/enalapril 20 mg (75.0%); this figure was 56.1% with the 10 mg/20 mg and 53.0% with the 10/10 mg combination. No safety concerns were reported. Conclusion: This pooled analysis of four randomized studies shows evidence of a dose-response effect in BP reduction with different fixed combinations of lercanidipine_enalapril. To our knowledge, this is the first analysis investigating the dose-response effect of a specific fixed-dose combination of antihypertensive agents. Further studies on this intriguing topic are however necessary.