Children using antiseizure medication more vulnerable to fragility fracture

Use of antiseizure medication (ASM) appears to carry an increased risk of fragility fracture in children with epilepsy, especially when treatment is initiated around the time of puberty, according to a study.

Children aged 4–21 years at baseline with at least 5 years of continuous health plan enrolment (to allow for a 1-year baseline and 4-years of follow-up) participated in the study. New ASM users with epilepsy were matched to nonusers without epilepsy, according to demographics and baseline fracture.

Age was categorized to provide a proxy for developmental stages, as follows: 4–6 (prepuberty), 7–10 (early puberty), 11–13 (mid-puberty), 14–17 (late puberty), and 18–21 (postpuberty) years.

Compared with ASM nonusers without epilepsy, new ASM users with the neurological disorder (n=1,205) had a 34-percent higher incidence of nontrauma fracture (NTFx) over 4 years of follow-up. The corresponding crude incidence rates (IRs) were 20.6 (95 percent confidence interval [CI], 16.5–24.8) and 15.4 (95 percent CI, 14.4–16.3), yielding an IR ratio (IRR) of 1.34 (95 percent CI, 1.09–1.66).

The pattern of NTFx incidence differed by age, such that new ASM users showed a more dramatic increase, with the incidence peaking at 11–13 years then decreasing at older years. The crude IRs and IRRs were elevated for new ASM users with epilepsy vs nonusers without the neurological disease for each age group (10–55 percent higher), but was only statistically significant in the 11–13-year age group (IRR, 1.55, 95 percent CI, 1.02–2.36).

In light of the present data, clinicians should consider age-appropriate adjunct bone fragility therapies.