SAN DIEGO – There are no discernible differences in the efficacy of the two most common antiepileptic drugs used in children with new-onset focal epilepsy, results from a retrospective cohort study found.
The drugs – levetiracetam and oxcarbazepine – had never been compared in a pediatric population before, Dr. Jenny L. Wilson said in an interview during a poster session at the annual meeting of the American Epilepsy Society.
Dr. Jenny Wilson
"This is not a randomized, controlled trial, but it’s still a very good measure of effectiveness of two very commonly used antiepileptic drugs for pediatric epilepsy," said Dr. Wilson, a child neurology resident at the Children’s Hospital of Philadelphia. "We’re showing that the retention rates are similar, and that efficacy is comparable to studies of older antiepileptic drugs. Retention rate is a practical outcome measure which takes into account the efficacy and tolerability of an antiepileptic medication. It’s some initial data for clinicians to consider when they’re making decisions about a first-line antiepileptic drug."
Dr. Wilson and her colleague, Dr. Sudha Kilaru Kessler, at the university reviewed the medical records of 221 children aged 1-17 years whose epilepsy was diagnosed within 3 months of their first visit to Children’s Hospital between January 2008 and June 2010. They excluded patients with status epilepticus, those who were hospitalized for more than 2 days at presentation, and those who had less than 6 months of follow-up data available, and used Kaplan-Meier methods to estimate the rates of drug failure, which was defined as discontinuation of the first antiepileptic drug (AED) or addition of a second AED.
Of the 221 patients, the median age at first seizure was 5.7 years, and the median age at initiation of AED therapy was 6.5 years.
The researchers reported findings from 1,435 person-months for levetiracetam and 2,137 person-months for oxcarbazepine. The rate of AED failure was 2.8/100 person-months in the levetiracetam group and 1.7/100 person-months in the oxcarbazepine group, a difference that did not reach statistical significance (hazard ratio, 0.7; P = .11). Among all children, the probability of remaining on the first AED was 76% at 6 months and 58% at 40 months, and drug failures due to lack of tolerability occurred sooner than failures due to a lack of efficacy (a median of 1.7 months vs. 4.56 months).
Univariate analysis revealed the following reasons for failure: lack of efficacy (12.4/100 person-months), tolerability (26.2/100 person-months), and both (17.8/100 person-months). "In my experience, kids with behavioral problems tend to fail levetiracetam a little bit more because of behavioral side effects," Dr. Wilson commented. "We did not see significant differences in that regard. The failure rates were very similar."
She concluded that the overall study results suggest that levetiracetam and oxcarbazepine "are very good first-line agents for new diagnosis of focal epilepsy in children" and emphasized that a randomized trial is warranted to confirm the findings.
The study was funded by the National Institutes of Health. The researchers stated that they had no relevant financial disclosures.