Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Zarontin (Ethosuximide).

Blood disorders: Blood disorders, although infrequent, may be serious and have been reported to be associated with the use of Zarontin (Ethosuximide). Zarontin (Ethosuximide) can decrease the number of neutrophils (a type of white blood cell that helps fight infection), red blood cells (which carry oxygen), and platelets (which help your blood to clot). Your doctor may do blood tests to monitor this. If you notice any signs of infection (e.g., fever, chills, or sore throat) or unusual bleeding or bruising, contact your doctor immediately.

Drowsiness/reduced alertness: Zarontin (Ethosuximide) may impair the mental or physical abilities required for potentially dangerous activities such as driving or operating machinery. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how Zarontin (Ethosuximide) affects you.

Liver function:  Liver disease or reduced liver function may cause Zarontin (Ethosuximide) to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how Zarontin (Ethosuximide) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Zarontin (Ethosuximide), and whether any special monitoring is needed.

People taking Zarontin (Ethosuximide) may have changes in liver function that produce abnormal liver test results. Your doctor will recommend regular liver tests while you are taking Zarontin (Ethosuximide).

Lupus: Cases of systemic lupus erythematosus (SLE) have been reported with the use of Zarontin (Ethosuximide). If you have SLE, discuss with your doctor how Zarontin (Ethosuximide) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Zarontin (Ethosuximide), and whether any special monitoring is needed.

Seizures: Zarontin (Ethosuximide) may increase the frequency of experiencing tonic-clonic, or grand mal seizures for people that experience mixed types of seizures. If you experience an increase in the number of seizures you have, or different types of seizures, contact your doctor as soon as possible.

Suicidal behaviour: People taking Zarontin (Ethosuximide) may feel that they want to hurt themselves or others. These symptoms may occur within several weeks after starting Zarontin (Ethosuximide).  If you experience these side effects or notice them in a family member who is taking Zarontin (Ethosuximide), contact your doctor immediately. You should be closely monitored by your doctor for emotional and behaviour changes while taking Zarontin (Ethosuximide).

Pregnancy: Women subject to major seizures should not stop taking Zarontin (Ethosuximide) during pregnancy. For women subject to minor seizures, the risk of stopping the medication prior to or during pregnancy should be weighed against the risk of birth defects. If you become pregnant while taking Zarontin (Ethosuximide), contact your doctor right away.

Breast-feeding: Zarontin (Ethosuximide) passes into breast milk. If you are a breast-feeding mother and are taking Zarontin (Ethosuximide), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of Zarontin (Ethosuximide) have not been established for children less than 3 years of age.