Description: Ethosuximide is an anticonvulsant, especially useful for petit mal or absence types of seizures, that acts by reducing the number of seizures in the brain. 


This medication is used alone or with other medications to prevent and control a certain type of seizure (absence or petit mal seizure).


Should not be given to patients with known severe allergic reaction to the drug.

How to use ethosuximide


For adults, initial dose is 500 mg by mouth daily, then dosage may be increased by small increments until seizure is controlled with less side effects.

For pediatric patients ages 3 to 6 years old, give 250 mg by mouth daily then increased until seizure is controlled.

For ages 6 to 18 years old, give 500 mg by mouth daily then increased until seizure is controlled.

  • Take this medication by mouth with or without food, usually once or twice daily or as directed by your doctor.
  • Your doctor will start you on a low dose and slowly increase your dose. It may take several weeks or months to reach the best dose for you and to get the full benefit from this medication.
  • Do not stop taking this medication without consulting your doctor. Some conditions may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased.

Blood dyscrasia: Problems in the blood have been reported with ethosuximide; therefore, periodic blood counts shoud be performed.

Liver and Kidneys:  Ethosuximide may cause liver and kidney changes.  Periodic urinalysis and liver function studies should be performed.

Systemic Lupus Erythematosus: Cases of systemic lupus erythematosus have been reported with the use of ethosuximide.

Suicidal thoughts or ideation: Patients who take ethosuximide may be at increased risk for suicidal thoughts or actions. The risk may be greater in patients who have had suicidal thoughts or actions in the past. Watch patients who take ethosuximide closely.

If any of the following symptoms of overdose occur while taking ethosuximide, get emergency help immediately:

Symptoms of overdose

  • Change in consciousness
  • irregular, fast or slow, or shallow breathing
  • loss of consciousness
  • pale or blue lips, fingernails, or skin

Some of the side effects that can occur with ethosuximide may not need medical attention:


  • Increased in sexual ability, desire, drive, or performance

increased interest in sexual intercourse



Monotherapy with ethosuximide in patients with mixed types of epilepsy may increase the probability of grand mal seizures in some patients.

Older adults may be more sensitive to the side effects of this drug, especially dizziness, loss of coordination, or fainting. These side effects can increase the risk of falling.

Dosage changes of ethosuximide, as well as, the addition and/or elimination of other medications should be done slowly. In addition, withdrawal of ethosuximide therapy should be done gradually.

  • Ethosuximide may impair the mental and/or physical abilities necessary for potentially hazardous tasks such as driving or operating machinery.
  • Liquid products may contain sugar and/or alcohol. Caution is advised if you have diabetes, alcohol dependence, liver disease, or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using this product safely.

Pregnancy Risk: During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

Breastfeeding: This medication passes into breast milk, but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.



  • Tell your doctor or pharmacist if you are taking other products that cause drowsiness, including alcohol, antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine).


If overdose is suspected, contact a poison control center or emergency room immediately.

Symptoms of overdose may include: slow/shallow breathing, severe drowsiness, loss of consciousness.


Do not share this medication with others.

Laboratory and/or medical tests (such as ethosuximide blood levels, complete blood count, kidney/liver function) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Missed Dose

It is important to take each dose at the scheduled time. If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.


Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not freeze the liquid form of this medication. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.



There are no brands containing this molecule.

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