Abstracts

RATIONALE: Since the introduction of Lamotrigine in the United States there has not been a large retrospective study evaluating efficacy and safety after long-term use. At the end of this activity participants will be able to determine the potential role of Lamotrigine therapy in treatment of multiple epilepsy syndromes
METHODS: We completed a retrospective analysis of 454 patients from 2 clinics starting from 1991, when Lamotrigine was first used in these clinics, to 2002. 116 patients were from a community-based Epilepsy Foundation clinic and the other 338 were from a university based epilepsy referral clinic. The average age of the patient population was 36 years old and the range of ages was from 3 to 96 years old. 24% were white, 13% were black, and 63% were Hispanic. Both primary and secondary generalized epilepsies were included, as well as simple and complex partial seizures. The primary endpoints were being seizure free for at 6 weeks and at 6 months.
RESULTS: Lamotrigine was helpful in the treatment of all types of seizures, regardless of age, sex, or race of patient, etiology of epilepsy, or length of time from diagnosis to initiation of Lamotrigine therapy. 80% of the Foundation clinic patients reported being seizure free at 6 weeks. Of the university referral clinic patients, 50% of those with complex partial seizures or secondary generalized seizures, and 60% of those with primary generalized seizures reported being seizure free 6 weeks after initiating Lamotrigine. In all populations, the percentage that remained seizure free at 6 months was approximately 50% of the percentage that were seizure free at 6 weeks. The average dose for the university referral clinic patients was 400mg daily and 18% were converted to monotherapy with Lamotrigine. Their average serum Lamotrigine level was 5mg/ml. 23% of all patients discontinued Lamotrigine. Only 7% discontinued the drug because of a rash, but there were no reports of life-threatening rashes. The most common reason for discontinuing Lamotrigine was no reduction in seizure frequency. In addition, there were several pregnancies during the study period, but there were no reports of fetal malformations directly attributable to the Lamotrigine.
CONCLUSIONS: Lamotrigine is an effective agent in the treatment of multiple epilepsy syndromes. This is true for both the economically selected patients seen in the community based Epilepsy Foundation clinic and the refractory patients seen in the university referral clinic. Lamotrigine is, however, somewhat less effective in refractory patients that have already been on multiple drug therapy in the past. Its side effect profile is equivalent to that of other anti-epileptic medications currently available.
[Supported by: University of Miami International Center for Epilepsy]