New antiepileptic drugs in practice--how do they perform in the real world?

Most large-scale clinical trials of antiepileptic drugs (AEDs) are undertaken for regulatory purposes and generate basic data supporting the efficacy and safety of a new treatment. They do not, however, provide all the information required for physicians to know how well the drug will work in clinical practice. One valuable approach to generating more clinically meaningful information is to assess AED treatment retention rates, which reflect the combination of efficacy and tolerability in the real world, and have historically been low. Long-term retention rate data are available for levetiracetam (LEV), topiramate, gabapentin, and lamotrigine, and these data suggest that LEV is more likely to retain patients than other new AEDs. In a recent tertiary care study involving mainly refractory patients, 11% of participants became seizure-free on LEV and nearly two-thirds were retained on long-term treatment. High seizure freedom rates and good tolerability reported with LEV in clinical trials thus appear to translate into improved treatment retention rates in clinical practice.