Antiepileptic drug prescribing patterns in Iraq and Afghanistan war veterans with epilepsy

Objective: We examined patterns of antiepileptic drug (AED) use in a cohort of Iraq/Afghanistan war veterans (IAVs) who were previously identified as having epilepsy. We hypothesized that clinicians would be more likely to prescribe newer AEDs and would select specific AEDs to treat seizures based on patient characteristics including gender and comorbidities.

Methods: From the cohort of IAVs previously identified with epilepsy between fiscal years 2009 and 2010, we selected those who received AEDs from the Veterans Health Administration in FY2010. Regimens were classified as monotherapy or polytherapy, and specific AED use was examine overall and by gender. Multivariable logistic regression examined associations of age; gender; race/ethnicity; medical, psychiatric, and neurological comorbidities; and receipt of neurology specialty care associated with the six most commonly used AEDs.

Results: Among 256,284 IAVs, 2123 met inclusion criteria (mean age: 33years; 89% men). Seventy-two percent (n=1526) received monotherapy, most commonly valproate (N=425) and levetiracetam (n=347). Sixty-one percent of those on monotherapy received a newer AED (levetiracetam, topiramate, lamotrigine, zonisamide, oxcarbazepine). Although fewer women than men received valproate, nearly 90% (N=45) were of reproductive age (≤45years). Antiepileptic drug prescribing patterns were associated with posttraumatic stress disorder, bipolar disorder, cerebrovascular disease, dementia/cognitive impairment, headache, and receipt of neurological specialty care (all p<0.01).

Significance: In this cohort of veterans with epilepsy, most received AED monotherapy and newer AEDs. Prescribing patterns were different for men and women. The patterns observed between AEDs and neurological/psychiatric comorbidities suggest that clinicians are practicing rational prescribing.