Abstracts

RATIONALE: Epilepsy is a common neurological disorder affecting almost 0.5-1 % of the population. Nearly 30% of patients with epilepsy are refractory to currently available drugs. Lamotrigine (LTG) is one of the newer antiepileptic drugs (AEDs) that is extensively studied in Europe and United States. It has better tolerability and wider spectrum than most. This study serves to establish the usefulness of LTG in the pediatric population of an academic referral center.
METHODS: An observational study was conducted with 35 children (23 F, 12 M) between the ages of 3 and 21 given LTG as either monotherapy or add-on therapy between the period of 4/00 - 4/02 with a mean duration of eigth months. Parameters followed were efficacy, length of treatment, side effects and the type of seizure. Initial dosing was as low as 2 mg every other day in younger patients on valproate with titaration up to 400 mg/d in older patients.
RESULTS: A total of 35 patients were observed, ten (28.5%) were withdrawn from the study, five (14.2%) due to lack of efficacy and five (14.2%) due to side effects.
Eight of the 35 patients developed side effects (22.8%): a rash in four, lethargy in three ( all were also on carbamazepine), and panic attacks in one patient. It was possible to restart the drug in three of the eight after adjusting the dose. One of the patients who had a rash was re-challenged at a slower titration and tolerated the medication well.
In the 25 patients who tolerated LTG, seizures were classified as generalized (n=15), partial with or without secondary generalization (n=12), BECTS (n=2), Lennox-Gastaut syndrome (n=2), and absence epilepsy (AE) (n=4). Associated disorders were present in the majority and included mental retardation, cerebral palsy, autism, traumatic and anoxic brain injury, and brain tumors.
Lamotrigine was used as monotherapy in 4 /25 (16%). all had primary generalized seizures and experienced complete control. It was used as add-on therapy in 21/25 (84%); 14/25 (56%) showed more than 50% improvement in the seizure control, especially when combined with phenytoin for partial seizures. The remaining 8/25 (22.8%) showed less than 50% improvement.
In this study LTG was more effective in generalized onset epilepsy than in partial. Three out of the four patients who has AE were seizure-free for more than one year. Three of these patients were switched from valproate either because of side effects (weight gain, hair loss), or lack of efficacy.
CONCLUSIONS: Our study adds to the positive clinical experience with LTG in terms of efficacy as a broad spectrum AED with a very good side effect profile. It indicates also that it is effective as monotherapy especially when used in AE. However the sample size was small, and further double-blinded, randomized studies needed especially in the primary generalized epilepsies.