Abstracts

Rationale: Clinical trials provide initial information on dosing, titration rates and adverse events (AE); however, data derived from the use of antiepileptic drugs (AED) in clinical practice is also necessary to assist physicians in the effective treatment of seizures. This study of the efficacy and tolerability of pregabalin (PGB) served as a pilot of the Post-marketing Antiepileptic Drug Surveillance (PADS) web-based registry. Methods: The titration rate and effectiveness of PGB in a large Midwestern epilepsy center was collected and analyzed for patients between 2005 and 2009. A retrospective medical chart review was performed for 95 patients (48 male, 47 female) who ranged from 11 to 86 years old (m=42). Chart reviews were performed for initial and 6-month follow-up visits, as well as seizure and AED history. Data was obtained using the PADS survey, a paper-based system developed by the PADS group, and entered into the pilot web-based PADS Registry. The PADS Registry is designed to compile and store extensive clinically relevant data collected from sites nationwide, thereby providing physicians with large and diverse research populations. Results: Of the patients prescribed PGB, 72 were diagnosed with localization-related epilepsy, 9 symptomatic generalized, 7 primary generalized, 2 Lennox-Gastaut and 1 juvenile myoclonic epilepsy. Prior to PGB, patients had previously been prescribed an average 6 AEDs (m=5.9). Patients were on an average 3 concomitant AEDs (M=2.7) when starting PGB. Of 95 patients, 13 (13.7%) achieved seizure freedom after 6 months on PGB. Twenty-three patients (24.2%) reported an improved seizure status; whereas, 27 (28.4%) reported a worsened condition. According to physicians charts, the global conditions of 40 patients (42.1%) had worsened, while improvement was noted in 12 (12.6%). Sixty-five patients (68.4%) reported at least one AE of any severity. Of those, 33 (34.7%) experienced severe AEs. Fatigue was the most frequent AE (n=29, 30.5%) with 16 experiencing severe cases, 12 of which resulted in discontinuation of PGB. Fourteen patients (14.7%; 10 female, 4 male) complained of weight gain (m=18lbs) and 12 (12.6%) reported dizziness. Other AEs included ataxia (10.5%), headaches (7.4%), blurred vision (6.3%) and psychomotor slowing (6.3%). Physicians discontinued PGB in 49 patients (51.6%) within 6 months; 35 (71.4%) discontinued due to AEs and 11 (22.4%) due to lack of efficacy. After 6 months, 46 patients (48.4%) remained on PGB; physicians modified the dosage for 12 (12.6%) of those patients. Conclusions: PGB was effective in improving seizure status in nearly 25% of patients; however, nearly 70% reported AEs. The most frequent AEs were fatigue, weight gain, dizziness, ataxia and headaches. The type of epilepsy syndrome did not affect the discontinuation rates. Additional data is required to determine the tolerability and effectiveness of PGB. This study served as a trial for the PADS Registry, which will expand to include other clinics nationwide in an attempt to compile sufficient data for specific analysis of PGB.