Safety comparisons among different subcutaneous anticoagulants for venous thromboembolism using FDA adverse event reporting system

Venous thromboembolism (VTE) remains a significant global health burden, particularly in older adults. While fondaparinux sodium, enoxaparin sodium, and dalteparin sodium are commonly used anticoagulants, their safety profiles require further evaluation. This study analyzes their adverse drug events (ADEs) using data from the FDA Adverse Event Reporting System (FAERS). A retrospective pharmacovigilance study was conducted using FAERS data from Q1 2004 to Q2 2024. Reports identifying fondaparinux sodium, enoxaparin sodium, or dalteparin sodium as the primary suspect drug were extracted. ADEs were classified using MedDRA 23.0 at the System Organ Class (SOC) and Preferred Term (PT) levels. Disproportionality analysis was performed with Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-item Gamma Poisson Shrinker (MGPS). FAERS contained 470 reports for fondaparinux sodium, 1,375 for enoxaparin sodium, and 344 for dalteparin sodium. Most cases involved patients aged ≥ 60, with a female predominance. Hospitalization was the most frequent outcome. Fondaparinux showed the strongest signals for intra-abdominal haematoma (ROR = 374.14, PRR = 371.14), muscle haemorrhage (ROR = 354.91, PRR = 347.04), and retroperitoneal haematoma (ROR = 214.97, PRR = 213.25). Enoxaparin demonstrated notable signals for heparin-induced thrombocytopenia (HIT) (ROR = 149.42, PRR = 147.53) and retroperitoneal haemorrhage (ROR = 287.68, PRR = 284.03). Dalteparin showed notable signals for HIT (ROR = 127.88, PRR = 126.49) and retroperitoneal haemorrhage (ROR = 103.23, PRR = 102.75). Distinct ADE profiles were identified among the three anticoagulants, underscoring the need for individualized risk assessment. These findings highlight the importance of close monitoring, particularly in high-risk patients, to optimize anticoagulation safety.