Antiepileptic

Antiepileptic, or antiepileptic drug (AED), refers to medications used to prevent or control seizures in people with epilepsy. AEDs may be used as lifelong monotherapy or as add-on therapy when seizures persist. They are also used for certain other conditions, such as neuropathic pain and migraine prophylaxis, and in the management of status epilepticus in acute care settings.

AEDs act through diverse mechanisms, often by reducing neuronal excitability or dampening excessive synchronization. Some drugs predominantly block voltage-gated sodium channels (e.g., carbamazepine, phenytoin, lamotrigine). Others enhance gamma-aminobutyric acid (GABA)–mediated inhibition (e.g., valproate, phenobarbital, benzodiazepines). Others act on calcium channels (ethosuximide for absence seizures) or counter excitatory glutamatergic transmission (some agents including perampanel). Many agents have multiple actions and may be selected based on seizure type and comorbidity.

Common AEDs include valproate, lamotrigine, levetiracetam, carbamazepine, oxcarbazepine, phenytoin, topiramate and phenobarbital. Valproate has broad efficacy but carries significant teratogenic risk; lamotrigine requires slow titration due to rash risk; carbamazepine and phenytoin are strong hepatic enzyme inducers with potential interactions; levetiracetam has fewer drug interactions; topiramate can cause cognitive effects and weight loss. Dosing is individualized and can require therapeutic drug monitoring for some agents.

Safety and monitoring include assessing seizure type, comorbidities, and potential adverse effects. Liver function and blood counts may be monitored with certain drugs; pregnancy considerations are critical, as some AEDs, notably valproate, markedly increase fetal risk and require counseling and folic acid supplementation. AEDs can interact with other medications; abrupt withdrawal can provoke withdrawal seizures. In acute care, benzodiazepines or IV AEDs may be used for status epilepticus.