Abstract
Background: Amlodipine has recently been incidentally reported with angioedema and is frequently prescribed with renin-angiotensin-aldosterone system inhibitors (RAAS-i) for hypertension management. While RAAS-i drugs are known to cause angioedema, the risk associated with amlodipine alone or in combination with RAAS-i drugs remains unclear. This study aimed to evaluate the association between amlodipine use and angioedema using pharmacovigilance data. Methods: We analyzed adverse event reports from the US FDA Adverse Event Reporting System using both frequentist and Bayesian approaches. Drug-drug interactions were assessed using multiplicative models. Additionally, we conducted a systematic review of published case reports of amlodipine-associated angioedema. Results: Among 29,661,136 reports, 2076 cases of angioedema were identified (1067 with amlodipine alone, 1009 with amlodipine-RAAS-i combinations). Significant safety signals were detected for amlodipine alone and in combination with aliskiren, specific ACE inhibitors (quinapril, benazepril, trandolapril, fosinopril, perindopril), and certain ARBs (candesartan, losartan). No significant interactions were observed between amlodipine and RAAS-i drugs except for the amlodipine-trandolapril combination. A review of published cases demonstrated definite causality in two cases and possible association in others, with most patients presenting with oropharyngeal/facial edema and achieving complete recovery following drug discontinuation and standard therapy. Conclusions: Our findings suggest a potentially increased risk of angioedema with amlodipine, both as monotherapy and in specific RAAS-i combinations. While these results should not discourage appropriate clinical use, they emphasize the importance of monitoring for angioedema, particularly during therapy initiation. The findings from this study need to be validated in prospective studies for further elucidation of the underlying mechanisms.