Mechanisms of action of antiepileptic drugs

Epilepsy affects up to 1% of the general population and causes substantial disability. The management of seizures in patients with epilepsy relies heavily on antiepileptic drugs (AEDs). Phenobarbital, phenytoin, carbamazepine and valproic acid have been the primary medications used to treat epilepsy for several decades. Since 1993 several AEDs have been approved by the US FDA for use in epilepsy. The choice of the AED is based primarily on the seizure type, spectrum of clinical activity, side effect profile and patient characteristics such as age, comorbidities and concurrent medical treatments. Those AEDs with broad-spectrum activity are often found to exert an action at more than one molecular target. This article will review the proposed mechanisms of action of marketed AEDs in the US and discuss the future of AEDs in development.