Abstracts

RATIONALE: To avoid adverse effects (AEs) from a slow and complex gradual transition from carbamazepine to oxcarbazepine (OXC) for patients with inadequately controlled partial seizures or intolerable side-effects, an overnight transition was designed.
METHODS: Twenty-five adult patients age 17-75 (16 female, 11 male) on carbamazepine monotherapy (n=13), dual AED therapy (n=9), or triple AED therapy (n=3) were transitioned off carbamazepine, stopping the medication with the last PM dose of day 1 and began OXC on day 2, continuing the same dose of OXC for at least a week, with all other AEDs unchanged, if present. Baseline seizure frequency ranged from 0 (1 patients with intolerable AEs) to 2-3/week, mean=4.48/mo. of simple partial, partial complex or secondary generalized. Baseline carbamazepine doses ranged from 200-1800 mg/day; mean=780 mg/day; 16 patients were on extended release CBZ. Transition OXC doses ranged from 300-2400 mg/day, mean=1236 mg/day, divided bid in 20 patients, tid in 5. A transition calculation of 1.0-2.0 times current carbamazepine dose was utilized to obtain the OXC transition dose (mean=1.58).
RESULTS: 25/25 patients tolerated the transition without discontinuing the drug. 20/25 experienced no transition side-effects. One discontinued due to a clear drug rash 2 weeks after initiation of OXC, two felt [dsquote]off balance,[dsquote] one felt clumsy and one experienced lethargy. All but the rash patient continued on the drug. 3/5 with AEs were on two or more other AEDs. Twenty-three of the patients had sodium values available after transition, 2 were [lt]125 meq/1, but [gt]120 meq/1. They were both asymptomatic and the drug was continued. No serious seizure exacerbations were experienced during transition.
CONCLUSIONS: An overnight transition from carbamazepine to oxcarbazepine can be effected safely with minimal adverse effects.
Support: Novartis
Disclosure: Grant - Novartis $10,000.00