Standard approach to antiepileptic drug treatment in the United States.

Antiepileptic drugs (AEDs) are administered to patients for acute and long-term treatment of seizures. Most patients with acute convulsions receive intravenous (i.v.) benzodiazepine (BZD), frequently followed by i.v. loading with phenytoin (PHT), especially when seizures continue. For patients with absence status epilepticus, BZD is usually followed by ethosuximide (ESM) or valproate (VPA). The decision to continue AED therapy is based on the likelihood that seizures will continue or recur. Once epilepsy is diagnosed, long-term treatment with AEDs is recommended, beginning with monotherapy. Two studies sponsored by the U.S. Veterans Administration (VA), which compared the efficacy of carbamazepine (CBZ), PHT, phenobarbital (PB), primidone (PRM), and VPA, recommend that most adults with recurrent partial seizures receive either CBZ or PHT. The 1992 VA study suggests that VPA is equal to CBZ or PHT in efficacy when partial seizures become secondarily generalized. Primary generalized epilepsies are most frequently treated with VPA when combinations of generalized seizures exist. ESM is prescribed most often when typical childhood absence seizures exist alone. Although many authorities do not recommend long-term treatment of childhood febrile seizures, PB is administered by some when febrile seizures have complex symptomatology. In general, AED monotherapy is currently preferred, but those with more refractory epilepsy receive polytherapy. CBZ, PHT, PB, PRM, VPA, and ESM are the primary AEDs prescribed in the United States. PHT, followed by CBZ and VPA, is the most frequently prescribed AED as both new and total prescriptions. The introduction of felbamate, gabapentin,and lamotrigine may alter these patterns in the future.