Weight Changes in Children and Adolescents with Epilepsy and Overweight/Obesity Treated with Zonisamide

Objective: To examine changes in weight status after initiating zonisamide in children with epilepsy and elevated body mass index (BMI). Study Design: Retrospective chart review of children aged 2 to ≤18 years with epilepsy treated with zonisamide, assessing BMI changes over 2 years. Results: A total of 140 children were included; mean age (SD) at initiation was 9.60 years (3.93). BMI categories included 28 children with severe obesity, 28 with mild–moderate obesity, 28 with overweight, and 56 with healthy weight. Participants were 56.6% female, 91.4% non-Hispanic/Latino, and 88.6% White. At 2 years, BMI z score decreased significantly across all BMI groups: severe obesity −0.38 ( N = 13, 95% CI −0.64 to −0.13; p = 0.003), mild-moderate obesity −0.39 ( N = 15, 95% CI −0.62 to −0.16; p = 0.001), overweight −0.60 ( N = 14, 95% CI −0.84 to −0.36; p < 0.001), and healthy weight −0.46 ( N = 21, 95% CI −0.63 to −0.28; p < 0.001). Significant BMI z score reductions were also observed across age groups: 2–10 years −0.48 ( N = 40, 95% CI −0.62 to −0.34), >10–13 years −0.27 ( N = 15, 95% CI −0.50 to −0.04), and ≥13 years −0.63 ( N = 12, 95% CI 0.89 to −0.36). Conclusions: BMI reduction persisted up to 2 years following zonisamide initiation in children with epilepsy. Further prospective studies are needed to evaluate the weight loss effect and safety of zonisamide in children with epilepsy and elevated BMI.