A Postmarketing Pharmacovigilance Study of Fenfluramine: Adverse Event Data Mining and Analysis Based on the US Food and Drug Administration Public Data Open Project (openFDA)

Background: A postmarketing analysis of the adverse events (AEs) associated with fenfluramine (FFA) was conducted using the US Food and Drug Administration's Open Public Data Program (openFDA). Methods: The openFDA database was queried to retrieve FFA AE reports. Two algorithms, namely, the reporting odds ratio (ROR) and proportional reporting ratio, were employed for the purpose of detecting potential safety signals. Results: From the openFDA data platform, a total of 6,269,521 AE reports were collected during the study period; the number of AE reports with FFA as the primary suspect was 2386. Of these, 1526 (63.96%) were reported by consumers or non-health professionals, 2009 (84.20%) were reported by the United States, 1053 (44.13%) were unknown indications, and serious AEs were reported in 1315 cases (55.11%). A total of 62 signals were generated. The top 10 signals included atonic seizures (ROR of 918.52, 95% confidence interval [CI]: 670.65-1257.99), seizure clusters (ROR of 787.02, 95% CI: 595.26-1040.56), mitral valve thickening (ROR of 773.94, 95% CI: 463.47-1292.38), pulmonary valve incompetence (ROR of 600.71, 95% CI: 432.09-835.13), echocardiogram abnormal (ROR of 417.13, 95% CI: 307.87-565.16), change in seizure presentation (ROR of 287.55, 95% CI: 214.81-384.91), tricuspid valve incompetence (ROR of 221.42, 95% CI: 179.68-272.84), aortic valve incompetence (ROR of 176.59, 95% CI: 131.89-236.45), tonic convulsion (ROR of 173.68, 95% CI: 110.28-273.54), and myoclonic epilepsy (ROR of 158.05, 95% CI: 102.60-243.46). Conclusions: This study employed the openFDA database to identify safety signals associated with FFA, thereby offering significant insights for clinical monitoring and risk identification in patients undergoing FFA therapy. (c) 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.