The EULEV cohort study: rates of and factors associated with continuation of levetiracetam after 1 year.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Levetiracetam has shown good safety/tolerability and efficacy in regulatory trials. This was confirmed in observational investigations performed soon after marketing by using continuation or retention rates as a composite measure. When an anti-epileptic drug first becomes available; however, there is evidence of channelling to more severe patients than thereafter. WHAT THIS STUDY ADDS: This study was performed several years after marketing of levetiracetam and found high rates of continuation. It also further explores this measure by determining the continuation in the absence of initiation of additional anti-epileptic drugs. AIMS: To investigate real-life effectiveness of levetiracetam in patients initiating treatment in a stable market situation. METHODS: Epileptic adults who had initiated levetiracetam between 1 January and 31 August in 2005 or 2006 were included and followed for 1 year by hospital or nonhospital neurologists practising in France. One-year continuation rates were estimated using Kaplan-Meier analysis. Among those still treated at end of study, treatment goals were investigated. Factors associated with discontinuation were investigated using Cox proportional hazards regression. RESULTS: A total of 794 subjects were included in the cohort, and 753 subjects were followed up and included in the analysis. Among these, mean (SD) age was 42.6 (±17.0) years, 51.1% were female, 76.6% had partial epilepsy, 93.5% had seizures in the 6 months preceding levetiracetam initiation and 82.9% had at least one concomitant anti-epileptic drug when starting levetiracetam. One-year levetiracetam continuation rate was 83.5% (95% confidence interval, 80.5-86.0%). Of the 579 patients still using levetiracetam at end of study, 46.8% were seizure free during the last 6 months, and 24% were on levetiracetam monotherapy. Reasons for discontinuation (n= 122) were adverse events (45%), lack of efficacy (38%) or both (9%). Levetiracetam discontinuation was most strongly associated with previous exposure to more than four anti-epileptic drugs, whereas continuation was most strongly associated with presence of seizure-related falls in the 6 months preceding levetiracetam initiation. CONCLUSIONS: This population-based cohort study in a stable market situation found a high 1 year levetiracetam continuation rate compared with previous studies done sooner after market introduction.