FELBAMATE
(Felbatol)

Indication: Felbamate is used for complex partial seizures that secondarily generalize. It has also been useful for children who have Lennox-Gastaut syndrome.

Possible side effects: The use of Felbatol is associated with a marked increase in the incidence of aplastic anemia (loss of the ability to make blood cells) and liver failure. Felbatol should be used only in those patients whose epilepsy is so severe that the risk of aplastic anemia is deemed acceptable in light of the benefits of therapy.

Felbatol as add-on therapy frequently interacts with other anticonvulsants to cause an increase (phenytoin) or a decrease (carbamazepine) in blood levels. When added to another anticonvulsant, the most frequent side effects reported were headache, nausea, vomiting, loss of appetite, sleepiness, dizziness, and insomnia. Nausea and vomiting were particularly common when felbamate was added to carbamazepine. These side effects often may stop after reducing the dosage of your other anticonvulsant.

You need to be aware that with any changes in your anticonvulsant therapy, there may be an increase in seizure frequency. Also, keep in mind that side effects vary among individuals. If you have any problem with medication, you should let your doctor know, whether or not it is a problem listed above.

Dosage: Felbatol is available in 400mg yellow and 600mg peach-colored scored tablets. Suspension is also available. In adults, the usual dose has been between 2400mg and 3600mg per day. If you are not having side effects and are still having seizures, your doctor may consider a higher dose.

Drug Interactions: Phenytoin and carbamazepine decreases while valproic acid increases felbamate levels. Felbamate increases phenytoin, valproic acid and carbamazepine epoxide levels and decreases the overall level of carbamazepine. Other drugs can affect or be affected by felbamate.

Blood levels: Because of Felbatol's interaction with other anticonvulsants, it may be necessary to monitor your other antoiconvulsant levels more frequently until your Felbatol dose is adjusted. The therapeutic level range for Felbamate has not been established.