Abstracts

Rationale: Post marketing analysis of anti-epileptic drug (AED) efficacy and tolerability is of great value to the clinician since it is more representative of clinical practice than clinical trial data. We analyzed our experience with lacosamide in patients treated after marketing. Methods: We identified all patients who were treated with lacosamide from the time of marketing in 2009 until 2013, excluding patients who were in clinical trials. The patients were identified from clinic panels of five different adult epileptologists. We recorded demographic data, seizure and epilepsy classification, baseline AEDs, seizure frequency before and after treatment, adverse experiences and the reason for discontinuation for those who stopped treatment. Efficacy analysis was made in patients who returned for follow up with at least three months of treatment. Tolerability analysis was possible for all treated patients who had at least one follow up visit or telphone call. Results: 165 patients (100 female) qualified for our study. Mean age was 41 years (154 patients were between ages 20 and 60 years). 139 patients had focal epilepsy, 13 had idiopathic generalized epilepsy and 13 had symptomatic generalized epilepsy. Lacosamide was added on to one AED in 36 patients (21.8%), two AEDs in 64 patients (38.8%), and three or more AEDs in 60 patients (36.4%). It was used in de novo monotherapy in 3 patients (1.8%) and conversion monotherapy in two patients (1.2%). The maintenance dose was =< 200 mg in 54 patients (32.7%), > 200-300 mg in 16 patients (9.7%), >300-400 mg in 48 patients (29.1%) and >400 mg in 47 patients (28.4%). Efficacy could be analyzed at 3 months in 140 patients. 37 (26.4%) had a >= 50% reduction in seizure frequency including 18 (12.9%) who were seizure free. 14 patients (10%) had worsening in seizure frequency. Seizure freedom rate increased to around 20% at 6 - 24 months of follow up. 80 (48.8%) patients were still continuing lacosamide at last follow up. Reasons for discontinuation were adverse effects (most commonly dizziness) in 45 patients (54.2%), lack of efficacy in 25 patients (30.1%), worsened seizures in 6 patients (7.2%) and other reasons in 17 patients (20.5%). Conclusions: Less than 50% of patients continued lacosamide therapy at follow up in clinical practice, but 13% of patients were seizure free at three months, with increase in seizure-free fraction to 20% thereafter.