- An ‘older’ but effective anticonvulsant.
- It is most used in primary generalised epilepsies, particularly CAE.
- There is now class 1 evidence for efficacy in CAE and it is regarded as the drug of choice.1
- 1Tracy A. Glauser et al.Ethosuximide, Valproic Acid, and Lamotrigine in Childhood Absence Epilepsy. N Engl J Med 2010; 362:790-799
Notable side effects
The main side effect is GI symptoms (abdominal pain). This is generally dose-dependent but can be intolerable and necessitate stopping the drug.
- Joint pain
- Drowsiness or lethargy
- All anticonvulsants are potentially teratogenic and this is often dose related (see section: AED Prescribing - Pregnancy)
For a complete list of adverse effects, appropriate formularies should be consulted.
- The initiation and escalation dose depends upon age, weight, syndrome, seizure frequency and severity, and side effect profile.
- Unfortunately, one dose regime does not fit all.
- A Paediatric Neurologist should be consulted if there is uncertainty.
Commonly used regime
- Start 10-15mg/kg/day in two divided doses increasing weekly.
- Around 20mg/kg/day is a reasonable target dose. Higher doses above 30mg/kg/day may be effective but GI symptoms are more frequent.
- Dosages per kilogram can only be used in children of weight approximately up to 30-40kgs.
- Maximum dosage in the older adolescent/adult range: 1500mg daily.
- Consult appropriate formularies for children with higher weights and in the adult range.
- These dosages are only a guide and appropriate formularies should be consulted as needed and tailored to the patient by the primary physician.
These dosages are only a guideline and appropriate formularies should be consulted as needed.
- 250mg capsule or 50mg/ml syrup forms.
No routine blood tests are necessary.
Interactions | Precautions
- No significant drug interactions occur.