Abstracts

Rationale: To describe differences in effectiveness and safety profile in patients treated with the most commonly prescribed AEDs in Germany transitioning to topiramate monotherapy (Topamax®, TPM).Methods: Multicenter, open label, observational study (TOPMAT-EPY-0001) examining patients >6 yrs diagnosed with epilepsy and prior insufficient treatment (lack of effectiveness and/or tolerability) with PHT, OXC, CBZ or VPA monotherapy and planned transition to TPM monotherapy. Patients were followed for 16 weeks after initiation of TPM.Results: The ITT analysis included 407 patients (53% female, no significant difference between groups) treated with VPA, CBZ, OXC or PHT. Mean age (±SD) over all groups was 45.8±16.8 yrs. Between-group comparisons were performed by the Chi2- or the Kruskal-Wallis-H-test. Patients on VPA or PHT were younger at diagnosis than patients on CBZ or OCX (p< 0.005), but epilepsy duration was longer in the PHT treated group (p<0.001). Overall, 75% of patients transitioned to TPM due to lack of efficacy (no differences between groups) and 61% due to insufficient tolerability (Chi2-test: p=0.067). TPM median dose at endpoint was 100mg/day. Overall, seizure frequency decreased from 2.35±5.4 per 4 weeks during the 12-weeks retrospective baseline to 1.14±4.05 during the prospective observational period (Wilcoxon- test: p<0.001). All patients showed a significant seizure reduction while transitioning. 64.2% of all patients had an at least 50% seizure reduction and 41.8% were seizure free during the entire documentation period. 51 AEs had at least a possible relationship to TPM treatment. Treatment-related AEs (>