n. an anticonvulsant drug, structurally related to meprobamate, that is thought to work by both enhancing the effects of the inhibitory neurotransmitter gamma-aminobutyric acid and inhibiting the effects of the excitatory amino acid glutamate (see NMDA receptor). Due to the increased incidence of aplastic anemia and hepatitis associated with this drug, it is less commonly used than other anticonvulsants; it is generally reserved for patients with severe epilepsy who respond inadequately to other treatments. U.S. trade name: Felbatol.