Felbamate (Felbatol - Wallace Laboratories), a phenyl dicarbamate structurally similar to meprobamate (Equanil, and others), was recently approved by the US Food and Drug Administration for use alone or with other drugs in adults with partial seizures with or without secondary generalization. It was also approved for use in addition to other drugs in children with the multiple types of seizures associated with the Lennox-Gastaut syndrome, a severe epileptic encephalopathy.

Lamotrigine (la mo tri jeen; Lamictal - Burroughs Wellcome), a phenyltriazine derivative, has been approved by the US Food and Drug Administration for use in addition to other antiepileptic drugs in adults with partial seizures. Since this diagnostic category includes the largest number of patients with intractable epilepsy, new drugs with antiepileptic activity are usually tried first for this indication. Lamotrigine was first marketed abroad in 1990 and is now available in more than 50 other countries.

Topiramate (Topamax - Ortho-McNeil) has been approved by the US Food and Drug Administration (FDA) for oral use as an adjunct to other drugs in adult patients with partial seizures. Since this diagnostic category includes the largest number of patients with refractory epilepsy, new drugs with antiepileptic activity are usually tried first for this indication. Topiramate (toe pyre' a mate) is a structurally unique agent chemically related to the D-enantiomer of fructose.

Gabapentin (Neurontin - Parke-Davis), a cyclohexane acetic acid derivative, has been approved by the US Food and Drug Administration for use in addition to other antiepileptic drugs in patients with partial (focal) seizures with or without secondary generalization. Since this diagnostic category includes the largest number of patients with intractable epilepsy, new drugs with antiepileptic activity are generally tried first for this indication.

Clobazam (Onfi – Lundbeck), an oral benzodiazepine, has been approved by the FDA for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients ≥2 years old. It has been available in Canada (Frisium) and other countries for years for treatment of anxiety and many types of epilepsy.

Tiagaine (Gabitril - Abbot), a gamma-aminobutyric acid (GABA) uptake inhibitor, has been approved by the FDA for oral use as an adjunct to other drugs for treatment of partial seizures in patients more than 12 years old. Since most adult patients with resistant epilepsy have partial seizures, new antiepileptic drugs are usually tried first for this indictation.

Rufinamide (Banzel - Eisai), a triazole derivative structurally unrelated to other marketed antiepileptic drugs (AEDs), has been approved by the FDA for treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients ≥4 years old.

The FDA has approved lacosamide (Vimpat - UCB Pharma) for oral or intravenous (IV) use as add-on therapy in adults with partial-onset seizures.

Zonisamide (Zonegran - Elan Pharma), a sulfonamide chemically unrelated to other antiepileptic drugs, has been approved by the FDA for adjunctive use in adults with partial seizures. Zonisamide has been available in Japan for more than 10 years.

Oxcarbazepine, which is chemically similar to carbamazepine, and levetiracetam, a pyrrolidine acetamide chemically unrelated to other antiepileptic drugs, are the sixth and seventh drugs approved by the US Food and Drug Administration in the last five years for oral use in partial seizures.