Felbamate
The approval of Felbamate (Felbatrol) for sale in August 1993 represented the first advance in the drug treatment of epilepsy (in humans) in the US in fifteen years. Although felbamate has proven to be effective in adults with partial seizures, serious side effects began to appear one year after it's release. These side effects include aplastic anemia and liver failure. Eleven people taking Felbamate died from these side effects. The incidence of serious side effects is estimated at 1 in 1,500 people. Due to the serious side effects, Felbamate is only used today to treat seizures in people that are refractory to all other medications.
In dogs refractory to all other medications, Felbamate has been effective in controlling partial seizures. Risks of serious side effects are reduced when Felbamate is used as the only anticonvulsant.
In addition to potential serious side effects, the use of Felbamate is limited in veterinary medicine by the short half life of this drug and the high cost of the drug.
Felbamate Facts:
Mean Elimination Half-Life: 4 - 6 hours
Time to Reach Steady State Concentrations: 24 hours
Target Serum Concentration: The therapeutic range has not been well established.
Adverse Effects: Serious side effects of aplastic anemia and liver failure are reported in humans. Side effects in dogs are unknown.
Monitoring: No monitoring protocols have been established, however, bile acid testing and CBC are recommended to monitor for liver disease and anemia.
Cautions and Warnings:
Discontinuing Therapy: As with any anticonvulsant, discontinuing therapy may cause seizures to occur.
Berendt, M, Clinical
Neurology in Small Animals-Localization, Diagnosis and Treatment
Braund, K G; Clinical Syndromes in Veterinary Neurology
Plumb, DC, Veterinary Drug Handbook
Plunkett, SJ; Emergency Procedures for the Small Animal Veterinarian
Ruehlmann D, Podell M, March P, Treatment of partial seizures and seizure
like activity with felbamate in six dogs
Thomas, W B Idiopathic Epilepsy in Dogs, Small Anim Prac Jane 2000,184-206
Tilley, LP, The 5 Minute Veterinary Consult
