Safety of combination therapy of azilsartan medoxomil and amlodipine: a population-based cohort study

OBJECTIVES: This study investigated the safety of azilsartan and amlodipine combination therapy versus other angiotensin receptor blockers (ARBs) and amlodipine in patients with hypertension. METHODS: We conducted a cohort study utilizing healthcare databases from Korea and Taiwan. Patients aged between 18 years and 75 years who were newly prescribed both an ARB and amlodipine within 6 months of hypertension diagnosis were included. Safety outcomes assessed were hypotension, angioedema, acute pancreatitis, hyperkalemia, hypokalemia, toxic liver disease, hepatic failure, nausea and vomiting, and fall-related injury. Hazard ratios (HRs) with 95% confidence intervals (CIs) for each safety outcome associated with azilsartan medoxomil and amlodipine versus other ARBs combined with amlodipine were calculated within a 1:1 propensity score (PS)-matched cohort. Summary HRs across databases were computed using random-effects meta-analysis. RESULTS: We identified 2,472 eligible patients (1,521 from Korea, 951 from Taiwan) initiating treatment with azilsartan medoxomil and amlodipine, and 671,468 patients (312,322 from Korea, 355,409 from Taiwan) initiating other ARBs with amlodipine. After PS matching, baseline characteristics were well-balanced between treatment groups. During the 180-day follow-up, most adverse outcomes did not occur even once in either group, thus precluding the calculation of HRs. The risk of acute pancreatitis was not significantly different between the azilsartan medoxomil and amlodipine group and the other ARB and amlodipine groups (summary HR, 0.86; 95% CI, 0.14 to 5.37). CONCLUSIONS: In this population-based cohort study, azilsartan medoxomil combined with amlodipine was not associated with an increased risk of adverse outcomes compared to other ARBs combined with amlodipine.