Outcome of treatment changes in patients with drug-resistant chronic epilepsy: A tertiary center experience

Background: Previous studies suggest that changing patients' anti-epileptic drug regimen can reduce the frequency of seizures. The approval of new anti-epileptic drugs with different modes of action during the last decades has provided multiple options for the treatment of epilepsy, although the efficacy of these new drugs is controversial. We aimed to determine the effects of adding or changing to a previously untried anti-epileptic drug, including recently approved drugs, on the frequency of seizures in patients with drug-resistant epilepsy. Methods: We analyzed treatment changes in drug-resistant patients at our outpatient clinic between 2010 and 2015. We classified patients' frequency of seizures after changes as freedom from seizures, >= 50% reduction, < 50% reduction, no change, increase in seizures < 50% or increase in seizures >= 50%. Results: We analyzed 189 drug changes in 144 consecutive drug-resistant patients followed up for at least 6 months after the change; 138 changes involved administering newly marketed drugs: lacosamide (n = 65), perampanel (n = 30), eslicarbazepine (n = 29), and retigabine (n = 14). Changes resulted in freedom from seizures in 20 (13.9%) patients and in >= 50% decrease in frequency in 55 (38.2%). The drugs most commonly associated with significant improvement (freedom from seizures or >= 50% reduction) were lacosamide (39.3%), dobazam (11.2%), and levetiracetam (11.2%). Conclusions: In patients with drug-resistant epilepsy, sequential changes increase the possibility of seizure control, and newer anti-epileptic drugs offer additional options for effective changes. Best combinations must be chosen taking into account drug, epilepsy and patient features.