Abstracts

Objective: At the end of this activity participants will be aware of the use of oxcarbazepine for epilepsy in tuberous sclerosis patients.
Oxcarbazepine is a novel anticonvulsant for partial epilepsy. It has a lower incidence of cognitive side effects than its parent compound carbamazepine. Its primary side effect relates to the idiosyncratic development of hyponatremia, which is increased in individuals with preexisting renal disease. We present our clinical experience with the treatment of epilepsy in 28 individuals with tuberous sclerosis using oxcarbazepine.
METHODS: The study group consisted of 15 males and 13 females. Genotype data was available for 16 patients, 15 had TSC 2 mutations and one had TSC 1 mutation. Oxcarbazepine was instituted at 10 mg/kg/day divided BID to TID. Dose was escalated by 5-10 mg/kg at 3-7 day intervals until either seizure control was noted, clinical toxicity occurred, or dosage of 60 mg/kg/day was achieved without significant reduction in seizures. Patients who experienced a significant (greater than 50%) reduction in seizures continued titration until optimal efficacy was achieved regardless of mg/kg dose. Monitoring included periodic determination of renal profile, hepatic profile, and CBC and differential.
RESULTS: 10 (36%) patients became seizure free, 6 (21%) experienced a greater than 50 % reduction (Total responders = 16). 12 (43%) did not respond, meaning a less than 50% reduction in seizure frequency. Oxcarbazepine was withdrawn in one patient due to cognitive slowing greater than that previously noted on carbamazepine. Otherwise no clinical significant side effects or hyponatremia were noted. No clinically relevant laboratory abnormalities were noted. No individuals experienced an exacerbation of seizures. Responders and non-responders did not vary significantly with regard to average tuber counts (13 vs. 14), autism (5 vs. 3), or history of infantile spasms (5 in each group). However 8 responders had normal intelligence compared to 2 non-responders.
CONCLUSIONS: We conclude that oxcarbazepine is a useful agent for the treatment of partial epilepsy associated with tuberous sclerosis, although apparently less effective than lamotrigine based on our previously published trial. ( Franz DN, et. al., Lamotrigine therapy of epilepsy in tuberous sclerosis. Epilepsia. 2001 Jul;42(7):935-40.) Its lower incidence of cognitive side effects and suitability for rapid dose escalation are valuable in this patient population.
[Supported by: Novartis Pharmaceuticals]; (Disclosure: Honoraria - Novartis Pharmaceuticals, Other - Financial support for abstract preparation - Novartis Pharmaceuticals)