Abstracts

Felbamate (FBM) was approved by the United States Food and Drug Administration in July 1993. From January to October 1994, 33 cases of aplastic anemia and 18 cases of hepatic failure were reported among users of FBM. Despite the risk of idiosyncratic adverse events, FBM appeared to be an effective antiepileptic agent in initial studies. There are limited post-marketing data available regarding the efficacy, safety and tolerability of FBM in pediatric epilepsy., We conducted a chart review of patients followed from January 2002 through May 2006 in the Pediatric Epilepsy Program at Massachusetts General Hospital. For each patient treated with FBM, we assessed demographics, seizure type and etiology, current and previous treatments, reported side effects of FBM, complete blood count (CBC) and liver function test (LFT) values, and efficacy of FBM treatment based on parental reports of percent seizure reduction. [chi]² and paired-sample T-tests were performed with SPSS v. 11.5., Forty-three (male/female 26/17) had been treated with FBM. Of the 43, 16 had partial onset seizures, nine had generalized seizures, and 18 had mixed seizure disorders. For 26 of the 43 patients, detailed data were available and this population was further evaluated. All of the 26 patients were treated with FBM in combination with other antiepileptic drugs or adjunctive therapy options.
Of the 26 patients, 11 patients experienced 50 to 90% reduction in seizures, and four experienced a greater than 90% seizure reduction. Seven patients experienced less than 50% reduction, and four had no change in their seizure frequency.
CBC and LFT values at 2 weeks, 1 month, and 3 months showed no significant alterations from baseline (N=14 at 2 weeks, N=16 at 1 month, and N=22 at 3 months) with the exception of the WBC count, which decreased from baseline (7.33[plusmn] 3.27 k/[mu]L) to 1 month (6.22 [plusmn] 2.54 k/[mu]L; 2-tailed P=0.009). Since this change in WBC was not accompanied by any other significant trends, and since WBC values at 2 weeks and at 3 months were not significantly altered from baseline, the etiology of the WBC decrease is unclear.
Two patients reported nausea and vomiting while on FBM. One patient died at 29 months of age while on FBM from respiratory and renal failure. Autopsy results suggested the patient died from a multisystemic disorder, not from an idiosyncratic reaction to FBM., Felbamate has been shown to be effective in the treatment of partial-onset seizures and Lennox-Gastaut syndrome. In our limited retrospective study, FBM appears to be well tolerated and efficacious in the treatment of refractory pediatric epilepsy. Although there were not significant side effects in our population, pediatric patients started on FBM should be closely monitored. Additional studies are needed to better define the role of FBM in pediatric epilepsy, both with regard to efficacy as well as tolerability.,