Absence Seizures: First-Line and Alternative Medications

First-Line Agents

• Ethosuximide (Zarontin): Gold standard for typical absence seizures. No effect on other seizure types.
• Valproate (Depakote): Broad-spectrum; effective for absence, generalized tonic-clonic, myoclonic. Teratogenic—avoid in pregnancy if possible.
• Lamotrigine (Lamictal): Effective for absence; slower titration required (rash risk). Preferred in women of childbearing potential.

Second-Line / Adjunctive Options

• Zonisamide (Zonegran)
• Clonazepam (Klonopin) — tolerance develops
• Clobazam (Onfi)
• Felbamate (Felbatol) — aplastic anemia/liver failure risk
• Levetiracetam (Keppra)
• Oxcarbazepine (Trileptal)
• Topiramate (Topamax)

Medications to AVOID

Carbamazepine, oxcarbazepine (paradoxically), phenytoin, phenobarbital, vigabatrin, tiagabine can worsen absence seizures.

Selection Factors

• Age, sex, reproductive plans
• Comorbid seizure types
• Side effect profile
• Drug interactions
• Insurance/formulary

Monitoring

EEG to confirm electroclinical response. Regular LFTs, CBC, and pregnancy tests as indicated. Counsel on adherence and avoidance of triggers (sleep deprivation, hyperventilation).