Abstracts

Medically refractory epilepsy (MRE) is often believed to require polypharmacy. Polypharmacy may increase side effects of medications, may interfere with medication metabolism and, paradoxically, may increase seizure frequency. We sought to evaluate the effect on seizure control and quality of life in a population of MRE patients converted from polypharmacy to monotherapy.
We retrospectively reviewed the charts of patients referred to our comprehensive epilepsy center with MRE. Patients who had failed adequate trials of two or more first-line antiepileptic drugs (AEDs) were designated as MRE (based on criteria set forth by Berg et. al. (Neurology 2003;60:186-190)). We identified patients who had been converted from polypharmacy to monotherapy and maintained on monotherapy for at least 12 months. We reviewed demographic data, diagnostic evaluation, seizure classification, and change in seizure frequency after the conversion. We conducted a QOLIE-31 questionnaire over the phone. The QOLIE-31 questionnaire was modified to compare patients[apos] experience on polypharmacy with the current monotherapy regimen.
We identified 35 patients ages 20-63 years (mean 39.8 years). The mean duration of epilepsy was 16.6 years. All patients were converted from polypharmacy to monotherapy using a variety of AEDs. The most frequently used polypharmacy combination was phenytoin and carbamazepine.
None of the 35 patients had worsening of their seizure frequency. Fourteen of the 35 patients (40%) became seizure-free after the conversion to monotherapy. Nine of 35 patients (26%) had a 50% reduction in seizure frequency. Five of 35 patients (14%) had a 75% reduction in seizure frequency. Overall 28 of 35 patients (80%) had a 50% or greater reduction in their seizure frequency with conversion to monotherapy and maintained that reduction for at least 12 months.
28 (80%) of 35 patients participated in a quality of life questionnaire. Six patients were unable to be contacted during the study period. One patient refused to participate in the questionnaire.
Five of the questionnaire parameters showed statistical significance at a p value of .01 or less. Improvement in state of health was statistically significant for patients on monotherapy compared to their experience on polypharmacy. Improvement on monotherapy compared to polypharmacy in memory loss, concern over medication long-term effects, difficulty in taking the medications and trouble with leisure time activities were all statistically significant.
Conversion to monotherapy in patients with MRE may be successful in achieving a reduction in seizure frequency and an improvement in quality of life parameters. A prospective, randomized trial is necessary to validate these findings.