Retention of new AEDs in institutionalized intellectually disabled patients with epilepsy.

Purpose: To assess the long-term usefulness of 'new anti-epileptic drugs (AEDs)' (lamotrigine, topiramate, levetiracetam, gabapentin and pregabalin) in institutionalized intellectually disabled patients. Information from RCTs is lacking in this population with severe intellectual and behavioural disabilities.

Methods: Retrospective study. Data from the medical files and the pharmacy databases of 118 institutionalized intellectually disabled patients who had ever used at least one of the new AEDs were analyzed. The main evaluation parameters were the duration of use (using Kaplan-Meier survival estimates) and the reason for discontinuation (lack of efficacy, occurrence of adverse events, or both) of the new AEDs. Drug continuation was based on the evaluation of treatment results by experienced epileptologists, and not on fixed criteria.

Results: New AEDs were generally tried only after a substantial number of other regimens (with classic AEDs) had failed. The most frequently used new AEDs were lamotrigine (68%) and levetiracetam (58%), followed by topiramate (28%) and gabapentin (8%). The 3-year retention rates were 70% (lamotrigine), 52% (levetiracetam), 51% (topiramate) and 33% (gabapentin). Discontinuation due to "lack of efficacy" occurred in 61% (topiramate), 60% (lamotrigine) and 42% (levetiracetam) of the cases. Discontinuation due to adverse events occurred in 42% (levetiracetam), 33% (topiramate) and 28% (lamotrigine).

Conclusions: Treatment of epilepsy with new AEDs was quite often successful in this very therapy-resistant population.