What is the role of antiepileptic drugs (AEDs) in the treatment of absence seizures?

Updated: Sep 25, 2018
  • Author: Scott Segan, MD; Chief Editor: Selim R Benbadis, MD  more...
  • Print
Answer

Answer

Only 2 first-line AEDs have approval from the US Food and Drug Administration (FDA) to be indicated for absence seizures: ethosuximide (Zarontin) and valproic acid (Depakene, Depacon). Ethosuximide has efficacy for absence seizures only and valproic acid has efficacy for absence, generalized tonic-clonic, and myoclonic seizures.

Ethosuximide (Zarontin) is effective only against absence seizures.

Valproic acid (Depakene, Depacon, Depakote, Depakote ER) is considered a broad-spectrum AED, because it is effective against absence, myoclonic, tonic-clonic, and partial seizures.

A study showed that ethosuximide and valproic acid were more effective than lamotrigine in the treatment of childhood absence epilepsy, and that ethosuximide had fewer adverse attentional side effects. [35]

Symptomatic generalized epilepsies are often refractory to first-line AEDs. Lamotrigine (Lamictal), topiramate (Topamax), and felbamate (Felbatol) are approved by the FDA as adjunctive therapy for the generalized seizures of Lennox-Gastaut syndrome in adult and pediatric patients (>2 y). Clonazepam (Klonopin) and the ketogenic or medium-chain triglyceride diet have been attempted to reduce seizure frequency. However, these adjunctive therapies have limited efficacy.

Of the newer AEDs, lamotrigine, topiramate, and levetiracetam have been shown to have efficacy against seizures in idiopathic generalized epilepsy [36, 37] and have received FDA approval to be indicated for adjunctive therapy of generalized tonic-clonic seizures in idiopathic generalized epilepsy in children aged 2 years and older (for lamotrigine and topiramate) and in children aged 6 years and older (for levetiracetam). Levetiracetam is indicated as adjunct therapy for generalized tonic-clonic and myoclonic seizures. It has been shown to have only modest efficacy against absence seizures. [38, 39]

Lamotrigine and topiramate are also approved as adjunctive therapy in Lennox-Gastaut syndrome in children aged 2 years and older. Rufinamide (Banzel) has been shown effective against typical and atypical absence seizures as well as other seizures in Lennox-Gastaut syndrome [40] and is approved as adjunct therapy in children older than 4 years.

Topiramate has also received FDA approval as initial monotherapy for generalized tonic-clonic seizures in children aged 10 years and older with idiopathic generalized epilepsy. Studies have shown these medications to have antiabsence efficacy, but the data are incomplete. [41]

Some AEDs can aggravate seizures, especially in cryptogenic or symptomatic generalized epilepsies. [42] Treatment with carbamazepine (Tegretol, Tegretol XR, Carbatrol) [43, 44] and oxcarbazepine (Trileptal) [45] has been associated with the exacerbation of absence seizures. Gabapentin (Neurontin) is ineffective against absence seizures, [46] and tiagabine (Gabitril) and vigabatrin (Sabril) have been associated with the exacerbation of absence or myoclonic seizures in some patients. [47]


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!