Because of concerns that it increases patients' risk of a few rare but serious disorders, Felbatol (felbamate) is used very rarely. For patients with severe epilepsy that is not well controlled by other seizure medicines, however, it may be worth considering, either alone or as an add-on. The patient must be fully informed of the risk before the treatment begins.

Felbatol is effective in treating partial seizures with and without generalization. A study that compared Felbatol alone with Depakote (valproate) alone in treating patients with previously uncontrolled partial seizures found a significant difference in favor of Felbatol (Faught et al. 1993). The patients who took Felbatol reported only mild or moderate adverse side effects, which were less common after other medications had been stopped.

Another study that did compare Felbatol to a placebo (with patients who were in the hospital for 10 days while being evaluated for epilepsy surgery) also showed that Felbatol is effective in controlling partial seizures when used alone (Devinsky et al. 1995).

Felbatol is also used as adjunctive (add-on) therapy for partial and generalized seizures associated with Lennox-Gastaut syndrome, a condition that is usually difficult to treat effectively. The 73 patients in one study continued to take their previous medications, to which was added either Felbatol or a placebo (Felbamate Study Group, 1993). After the dosages had been stabilized, the patients given felbamate had 26% fewer seizures than during the baseline period, compared with a 5% increase among the patients given the placebo. Unfortunately, the serious side effects caused by Felbatol in some people limits its use to patients who have not responded to other antiepileptic drugs.