2026 Eastern States Conference

Intravenous versus subcutaneous enoxaparin for the treatment of venous thromboembolism in the pediatric population

Authors: Brandon Ho, PharmD; Kelsey Mueller, PharmD, BCPPS; Kelly Lunsford, PharmD; Colleen Druzgal, MD

Learning Objective: The audience will be able to compare the safety and efficacy of intravenous (IV) enoxaparin compared to subcutaneous (SC) enoxaparin for the treatment of venous thromboembolism (VTE) in pediatric patients.

Background/Objective: SC enoxaparin is a common agent for pediatric venous thromboembolism but can be limited by pharmacokinetic variability and injection-site complications. Data for IV enoxaparin are limited, though it is used in other health systems.

Methods: This retrospective cohort study included hospitalized pediatric patients (<18 years) treated for venous thromboembolism with IV or SC enoxaparin at the University of Virginia (UVA) Health Children’s Hospital. Patients were excluded if they received oral anticoagulation prior to enoxaparin initiation or were diagnosed and treated with enoxaparin for venous thromboembolism prior to their admission at UVA. The primary outcome was a composite of anticoagulation failure and bleeding events. Secondary outcomes included time to therapeutic anti-Xa levels, dosing requirements, and time in therapeutic range. Categorical variables were analyzed using chi-square or Fisher’s exact tests, and continuous variables using Mann–Whitney U tests.

Preliminary Results: A total of 119 patients were included (IV n=47, SC n=72). The primary outcome occurred in 23.4% of IV patients and 22.2% of SC patients (p=1). Differences in the composite outcome were driven primarily by higher rates of new VTE in the IV group (17% vs 4.2%, p=0.02), while rates of progression, recurrence, bleeding, and lack of radiologic response were similar. Initial dosing and achievement of therapeutic anti-Xa levels were similar between groups, but patients in the IV group had less time spent in therapeutic range compared to the SC group (67.4% vs 72.7%, p = 0.31).

Conclusion: IV enoxaparin demonstrated similar overall safety outcomes compared to SC administration in hospitalized pediatric patients. However, the IV group had higher rates of new VTE and more difficulty maintaining therapeutic anti-Xa levels, potentially related to greater baseline clinical complexity and variability in anticoagulation control in the IV group. Further studies are needed to better define optimal dosing and monitoring strategies for IV enoxaparin in pediatric patients.

Self-Assessment Question: Does IV enoxaparin provide superior maintenance of therapeutic anti-Xa levels compared to SC enoxaparin for the treatment of VTE in pediatric patients?