Comparison of the Efficacy and Safety of Fixed-dose S-Amlodipine/Telmisartan and Telmisartan in Hypertensive Patients Inadequately Controlled with Telmisartan: A Randomized, Double-blind, Multicenter Study

Abstract

Purpose: The objective of this study was to evaluate the efficacy and safety of the fixed-dose combination S-amlodipine plus telmisartan (S-AM/TEL) compared with TEL monotherapy in patients with hypertension inadequately controlled by TEL monotherapy.

Methods: this study was a randomized, multicenter, double-blind, parallel group, Phase III, 8-week clinical trial to compare the superiority of the S-AM/TEL 2.5/40-mg and S-AM/TEL 5/40-mg combinations with TEL 80-mg mono-therapy. The primary end point was the change in the mean sitting diastolic blood pressure from baseline (week 0) after 8 weeks of therapy between treatment groups.

Findings: Of 325 patients screened, 183 were randomly assigned to 3 groups (61 in the S-AM/TEL 2.5/40-mg group, 60 in the S-AM/TEL 5/40-mg group, and 62 in the TEL 80-mg group). Mean (SD) age was 53.9 (7.5) years, and male patients comprised 87%. No significant differences were found among the 3 groups in baseline characteristics. The primary end points, the changes of mean (SD) diastolic blood pressure at week 8 from the baseline were -10.56 (7.23) mm Hg in the S-AM/TEL 2.5/40-mg group, -12.32 (9.23) mm Hg in the S-AM/TEL 5/40-mg group, and -2.44 (7.92) mm Hg in the TEL 80-mg group. Both the S-AM/TEL 2.5/40-mg group and the S-AM/TEL 5/40-mg group had a statistically superior hypotensive effect compared with the TEL 80-mg group (P < 0.0001 for both). For evaluation of the safety profile, the frequencies of adverse events (AEs) among the groups were also not significantly different (S-AM/TEL 2.5/40-mg group, 18.6%; S-AM/TEL 5/40-mg group, 20%; and TEL 80-mg group, 22.6%), and the incidences of AEs were not different among the groups. The most common AEs were respiratory disorders, followed by headache, dizziness, and peripheral edema.

Implications: Treatment with S-AM/TEL 2.5/40 mg and S-AM/TEL 5/40 mg was superior to increasing the TEL dose in terms of hypotensive effect in patients with hypertension inadequately controlled by TEL monotherapy. S-AM/TEL fixed-dose combinations are an effective and tolerable option for patients inadequately responding to TEL monotherapy and also a good option for improving patients' medication adherence. ClinicalTrials.gov identifier: NCT011426100.

Keywords: S-amlodipine; blood pressure; fixed-dose combinations; hypertension; single-pill combination; telmisartan.