Ethosuximide is an anti convulsant used to control seizures/fits. It is one of the “older” anticonvulsants and has been in use for many years. It is among the most effective anti convulsant drugs used for the treatment of childhood absence epilepsy.

It must be prescribed by a doctor. You should never give your child anyone else's medications.

Side effects

All medications have side effects. Not everyone will experience side effects.

Below are some of the possible side effects your child may experience:

Abdominal pain

  • This is the main side effect and is often dose dependant. At times it can be intolerable and the drug may need to be stopped. Sometimes, if the medication is  taken at the end of a meal, the side effects may decrease.


  • If your child develops a rash, there are important  features to look for such as: your child may develop red eyes, red mouth, blisters around the mouth, nose and lips.
  • If your child develops a rash or any of these signs please call your doctor immediately or go to the nearest Emergency Department.  The drug needs to be stopped immediately under medical supervision.

Blood disorders

  • Low white cell count.

Other side effects

  • Nausea
  • Vomiting
  • Diarrhoea
  • Headaches
  • Hiccoughs (hiccups)
  • Joint pain
  • Drowsiness or lethargy

Other possible side effects

  • Bruising
  • Irritability, depression and very rarely, psychosis
  • Abnormal movements
  • Weight loss


Your Doctor will check and make sure that other drugs your child is taking are compatible with Ethosuximide. This is also important if you are giving your child herbal or complementary medicines. The doctor can check to make sure they are compatible.


The medication should be used with caution in children with liver or kidney problems.

Monitoring and medication levels

There is no need to do regular blood monitoring with Ethosuximide. Some doctors may want to do a baseline blood test before starting the drug and infrequent subsequent tests of blood count and liver function. The only other monitoring required is a seizure diary to see if there is a decrease in the number of seizures.


Pregnancy and contraception

If a pregnancy is planned, a discussion with your neurologist is recommended. For further information, refer to the Contraception and Pregnancy section.



The information provided in this handout is limited and does not replace the need for a medical consultation. It is very important you speak to your doctor about all aspects of your medication including side effects when medication is first prescribed. Report any concerns to your doctor promptly.