Peri-marketing surveillance of lamotrigine in the Netherlands: Doctors' and patients' viewpoints

Purpose: Evaluation of daily clinical practice in prescribing lamotrigine i n refractory epilepsy patients. Methods: A collaborative, retrospective, peri-marketing study was performed in in- and out-patients attending one of the three Dutch epilepsy centres. Analysis of both patients' and doctors' information was performed in 520 p atients using questionnaires and medical files. Results:After one year of treatment 76% of patients maintained LTG treatmen t, an intention-to-treat analysis showed >= 50% seizure reduction in 23% of patients; 20-50% seizure reduction in 23% of patients. Six percent of pati ents became at least three months seizure free. In about 20% of patients se izures became less severe and shorter of duration, while in 6% an increase was found. After three months a significant decrease in number of concomita nt antiepileptic drugs was found (change from mean 1,8 to 1,5 AEDs) (p=< 0. 01). After twelve months the mean number of AEDs was 1,4 per patient. Overa ll percentage of side effects appeared to be significantly higher if patien ts' questionnaire data were used. Epilepsy patients considered side effects as an important factor in the choice of medication and in withdrawal of me dication. Future developments of new AEDs should take this into account. Conclusion: This perimarketing study gives insight information about long-t erm daily use of lamotrigine, with emphasis on effectiveness. Patients comp lained in the questionnaires much more about side-effects, than was known a ccording to the medical file. Therefore, it seems necessary to perform peri marketing studies more systematically.