Efficacy and Tolerability of a Fixed-Dose Combination of Metoprolol Extended Release/Amlodipine in Patients with Mild-to-Moderate Hypertension

Abstract

Epidemiological studies and clinical trials have shown that prevention of cardiovascular disease, the ultimate goal of hypertension treatment, requires a sufficient reduction in blood pressure. The primary objective of this study was to compare the mean decrease in systolic (SBP) and diastolic (DBP) blood pressure between metoprolol extended release (XL)/amlodipine fixed-dose combination and losartan plus amlodipine combination in patients with mild-to-moderate essential hypertension. The secondary objectives of this study were to compare the proportion of responders in the two treatment groups and to evaluate the tolerability of the study medications. This was a randomized, parallel-group, multicentre comparative study conducted at the outpatient departments of three teaching hospitals in India. Patients with mild-to-moderate hypertension (defined as DBP 90-109 mmHg) aged between 18 and 75 years were enrolled in this study and followed up for 12 weeks. Response to study treatments was evaluated in terms of mean decrease in SBP and DBP and the response rate (reduction to SBP <140 mmHg and DBP <90 mmHg). Out of 152 patients who underwent a 1-week placebo washout, 148 eligible patients were randomized to receive either metoprolol XL 25 mg/amlodipine 2.5 mg fixed-dose combination (76 patients) or losartan 25 mg plus amlodipine 2.5 mg (72 patients). The two treatment groups were similar with respect to demographic and baseline characteristics. Non-responders after 4 weeks of therapy were escalated to metoprolol XL 50 mg/amlodipine 5 mg fixed-dose combination or losartan 50 mg plus amlodipine 5 mg, respectively. The study was completed by 66 patients in each group, of whom 43 patients in each group responded to the starting doses. After 4 weeks' therapy, both treatments were associated with significant decreases in SBP and DBP from baseline (p < 0.001) and were comparable with respect to mean decrease in SBP (p = 0.304), mean decrease in DBP (p = 0.630) and response rate (p = 1.0). Also, both the step-up therapies were comparable with respect to mean decrease in SBP (p = 0.484), mean decrease in DBP (p = 0.650) and response rate (p = 0.134) at week 12. Both treatments were well tolerated in the studied population. Metoprolol XL/amlodipine fixed-dose combination was found to be as effective and well tolerated as losartan plus amlodipine in the treatment of essential hypertension.