Zonisamide Was Linked To Weight Loss In Children

What was studied

This study looked at weight changes after starting zonisamide in children and teens with epilepsy. The researchers reviewed past medical charts rather than assigning treatment in a trial. They included 140 patients ages 2 through 18 years who were treated with zonisamide and assessed body mass index (BMI) changes for up to 2 years.

At the time zonisamide was started, the group included children with healthy weight, overweight, mild to moderate obesity, and severe obesity. The average age was about 9.6 years. Most participants were female, White, and non-Hispanic/Latino.

What they found

At 2 years, BMI z-scores decreased across all BMI groups, including children with overweight, obesity, severe obesity, and healthy weight. The reported decreases were statistically significant in each BMI group with 2-year data.

BMI z-scores also decreased across the age groups studied. The authors reported that BMI reduction persisted for up to 2 years following zonisamide initiation in children with epilepsy.

Limits of the evidence

This was a retrospective chart review, so it cannot show from this study alone that zonisamide caused the weight changes. There was no comparison group of similar children with epilepsy who did not take zonisamide.

The number of children with 2-year data in each subgroup was small, even though 140 children were included overall. The study also does not provide enough detail to assess how other factors may have affected weight. Most participants were White and non-Hispanic/Latino, so the findings may not apply equally to all children.

For families and caregivers

For families, this study suggests that BMI went down over time in some children and teens with epilepsy after zonisamide was started, including those with overweight or obesity. This may be relevant when doctors consider possible weight-related effects of seizure medicines.

At the same time, this study does not show whether zonisamide was the reason for the BMI change or whether such changes are helpful or safe for every child, including children who are already at a healthy weight. Families should not assume the medicine should be used mainly for weight loss; its main role is seizure treatment.

What to watch next

The abstract says further prospective studies are needed to evaluate the weight loss effect and safety of zonisamide in children with epilepsy and elevated BMI.

Terms in this summary

zonisamide

A medicine used to help prevent seizures.

BMI

Body mass index, a measure that uses height and weight to estimate body size.

BMI z-score

A way to compare a child's BMI with what is typical for children of the same age and sex.

retrospective chart review

A study that looks back at information already recorded in medical charts.

statistically significant

A result that is unlikely to be due to chance alone, based on the study's calculations.