Adverse Events of Factor Xa Inhibitors in Pediatric Patients: A Meta-analysis and Pharmacovigilance Study

This study aimed to provide a comprehensive review of adverse events (AEs) associated with factor Xa (FXa) inhibitors in pediatric patients.

We searched PubMed, Embase, Cochrane Library, ClinicalTrials.gov, and the European Union Clinical Trials Register for English-language records from the establishment of the database up to October 17, 2023. Both randomized controlled trials and single-arm trials were included. AEs were analyzed using a Bayesian hierarchical model. For the pharmacovigilance study, data from the US Food and Drug Administration Adverse Event Reporting System from January 1, 2007, to December 31, 2023, were obtained. The proportional imbalance method and the Medicines and Healthcare products Regulatory Agency method were used to detect AE signals. Further characterization of patients presenting with AEs was performed.

Of 451 records identified, 12 eligible studies were included. A total of 50.6% (95% Bayesian credible interval [CrI] 33.1-67.2, τ = 0.796) of patients experienced at least one AE, and 9.9% (95% CrI 3.9-19.5, τ = 0.552) developed at least one serious AE. Major and clinically relevant non-major bleeding occurred in 2.4% (95% CrI 0.8-4.8, τ = 1.61) of patients. The most common bleeding AEs were epistaxis (8.4% [95% CrI 3.9-14.9, τ = 1.96]), subcutaneous hematoma (6.4% [95% CrI 0.5-26.2, τ = 0.54]), and wound hemorrhage (3.7% [95% CrI 0.4-13.3, τ = 0.55]). Non-hemorrhagic AEs were pyrexia (9.2% [95% CrI 4.6-15.3, τ = 1.18]), vomiting (7.8% [95% CrI 4.0-12.3, τ = 0.08]), and abdominal pain (7.4% [95% CrI 1.5-19.4, τ = 0.84]). A total of 39 AE signals were detected in the pharmacovigilance study. The top three highest overall relative odds ratio (ROR) for AEs were observed for haemorrhoidal hemorrhage at 1211.82 (95% CI, 312.69-4696.29), thrombophlebitis at 134.64 (95% CI, 42.18-429.81), and deep vein thrombosis at 68.3 (95% CI, 42.53-109.68). Patients experiencing bleeding AEs had received a mean dosage of rivaroxaban 0.16 mg/kg and apixaban 0.08 mg/kg.

Systematically quantified AEs of FXa inhibitors in clinical trials and real-world studies provide an important guide for clinicians. The use of FXa inhibitors in pediatric patients is associated with an acceptable rate of AEs. The most common bleeding AE was epistaxis. Pediatric patients treated with FXa inhibitors were more prone to hemorrhoidal hemorrhage. A safe approach may involve prior use of other anticoagulants followed by careful administration of FXa inhibitors, with a dosing regimen tailored to age and weight. Close monitoring is recommended for peri-procedural anticoagulation and vomiting.