Childhood absence epilepsy
ICD-10 G40.3 · ICD-11 8A61.21

Treatment of Childhood Absence Epilepsy with Absence Seizures Only When Ethosuximide Has Not Achieved Seizure Freedom

Clinical scenario

This protocol addresses children with childhood absence epilepsy (CAE) in whom absence seizures are the only seizure type and who have no history of generalised tonic-clonic seizures — and who have not achieved seizure freedom on first-line therapy with ethosuximide.

Prior line did not meet its goals — escalation is indicated

Ethosuximide (ETX) is the drug of choice for initial monotherapy in CAE when absence seizures are the only seizure type. When a full course of ethosuximide — titrated weekly over months and continued for 16–20 weeks — fails to eliminate both clinically apparent absence seizures and electrographic seizures on EEG, or when ETX is not tolerated, a change in treatment is indicated.

Next-line treatment approach

After ethosuximide failure — whether due to inadequate seizure control or tolerability — evidence supports transitioning to a specific alternative oral antiepileptic agent. The full structured protocol specifies the agent, titration approach, and decision rules for this population.

Treatment goals
  • Freedom from absence seizures by parent report
  • No electrographic seizures on EEG
  • Serum drug level within the established therapeutic range
Instant Access to Structured Evidence-Based Regimens

References

  1. The treatment of choice for CAE with absence seizures only is ethosuximide.
  2. Therefore, based on the CAE trial, ETX is the drug of choice as initial monotherapy for CAE, when absence seizures are the only seizure type, but there are specific treatment considerations for each drug, which are discussed below.
  3. Persistent seizures or AE on ETX, or presence of GTC seizures: Treat with VPA
  4. VPA is also preferred as a second treatment when ETX fails, whether due to efficacy or tolerability reasons, based on a crossover extension phase of the CAE study.
  5. The target serum level is the level at which absence seizures stop occurring, both by parent report and by EEG — that is, there is no need to increase the dose to reach an arbitrarily set serum level.
  6. However, for most patients, the therapeutic range is 50–100 µg/dL, and in the absence of side effects, serum levels can be pushed even higher to 120 µg/dL, or perhaps even 150 µg/dL.
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