Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

  1. Zarontin

Descriptions


Ethosuximide is used to control absence (petit mal) seizures in patients with epilepsy. This medicine is an anticonvulsant that works in the brain tissue to stop seizures.

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

  • Syrup
  • Capsule, Liquid Filled

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of ethosuximide in children. However, safety and efficacy have not been established in children younger than 3 years of age.

Geriatric

No information is available on the relationship of age to the effects of ethosuximide in geriatric patients.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Calcifediol
  • Fosphenytoin
  • Orlistat
  • Phenytoin
  • Valproic Acid

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Ginkgo
  • Nevirapine
  • Phenobarbital

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Blood or bone marrow problems or
  • Depression, history of or
  • Kidney disease or
  • Liver disease or
  • Mental health problems, history of or
  • Systematic lupus erythematosus (SLE)—Use with caution. May make these conditions worse.

Proper Use

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine comes with a Medication Guide. Read and follow the instructions carefully. Ask your doctor if you have any questions.

This medicine can be used with other seizure medicines. Keep using all of your seizure medicines unless your doctor tells you to stop.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • For seizures:
      • Adults and children 6 years of age and older—Dose is based on body weight and must be determined by your doctor. The starting dose is usually 500 milligrams (mg) once a day. Your doctor may increase your dose as needed.
      • Children 3 to 6 years of age—Dose is based on body weight and must be determined by your doctor. The starting dose is usually 250 mg once a day. Your doctor may increase your dose as needed.
      • Children younger than 3 years of age—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions

It is very important that your doctor check your progress closely while you or your child are using this medicine to see if it is working properly and to allow for a change in the dose. Blood and urine tests may be needed to check for any unwanted effects.

Do not stop taking this medicine without first checking with your doctor. Stopping the medicine suddenly may cause your seizures to return or to occur more often. Your doctor may want you or your child to gradually reduce the amount you are using before stopping completely.

This medicine may increase the chance of experiencing grand mal seizures in certain patients. Talk with your doctor if you have concerns about this risk.

Ethosuximide may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you, your child, or your caregiver notice any of these side effects, tell your doctor or your child's doctor right away.

This medicine may increase your risk of having systemic lupus erythematosus (SLE). Tell your doctor right away if you or your child has chest pain, fever and chills, general feeling of discomfort or illness, hair loss, headache, muscle or joint pain, skin rash, sore throat, swollen glands, or trouble breathing.

This medicine will lower the number of some types of blood cells in your body. Because of this, you may bleed or get infections more easily. To help with these problems, avoid being near people who are sick or have infections. Wash your hands often. Stay away from rough sports or other situations where you could be bruised, cut, or injured. Brush and floss your teeth gently. Be careful when using sharp objects, including razors and fingernail clippers.

Tell your doctor right away if you or your child feels unusually weak, starts bruising easily, has bleeding gums or nosebleeds, seems to be sick more often, has a fever, swollen glands, or a sore throat that will not go away.

Call your doctor right away if you or your child start to have persistent cough, weight loss, night sweats, fever, chills, or flu-like symptoms such as runny or stuffy nose, headache, blurred vision, or feeling generally ill.

Serious skin reactions, including Stevens-Johnson syndrome and drug reactions with eosinophilia and systemic symptoms (DRESS) can occur with this medicine, which can be life-threatening. Check with your doctor right away if you have black, tarry stools, blistering, peeling, or loosening of the skin, chest pain, chills, cough, diarrhea, itching, joint or muscle pain, painful or difficult urination, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, swollen glands, unusual bleeding or bruising, or unusual tiredness or weakness while you or your child are using this medicine.

Ethosuximide may cause dizziness, drowsiness, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Rare

  1. Changes in behavior
  2. discouragement
  3. feeling sad or empty
  4. irritability
  5. lack of appetite
  6. loss of interest or pleasure
  7. mood or mental changes
  8. thoughts of killing oneself
  9. tiredness
  10. trouble with concentrating
  11. trouble with sleeping

Incidence not known

  1. Bleeding gums
  2. blistering, peeling, or loosening of the skin
  3. blood in the urine
  4. bloody, black, or tarry stools
  5. chest pain
  6. cough or hoarseness
  7. diarrhea
  8. enlarged gums
  9. false or unusual sense of well-being
  10. fever with or without chills
  11. general feeling of discomfort or illness
  12. hair loss
  13. headaches
  14. high fever
  15. hives, itching, skin rash
  16. joint or muscle pain
  17. lower back or side pain
  18. nervousness
  19. not able to concentrate
  20. painful or difficult urination
  21. pale skin
  22. pinpoint red spots on the skin
  23. red skin lesions, often with a purple center
  24. red, irritated eyes
  25. restlessness
  26. shakiness and unsteady walk
  27. sore throat
  28. sores, ulcers, or white spots on the lips or in the mouth
  29. swelling around the eyes
  30. swelling of the tongue
  31. swollen, painful, or tender lymph glands in the neck, armpit, or groin
  32. trouble sitting still
  33. trouble breathing
  34. unsteadiness, trembling, or other problems with muscle control or coordination
  35. unusual bleeding or bruising
  36. unusual tiredness or weakness
  37. vaginal bleeding
  38. vision changes
  39. yellow eyes or skin

Get emergency help immediately if any of the following symptoms of overdose occur:

Symptoms of overdose

  1. Change in consciousness
  2. irregular, fast or slow, or shallow breathing
  3. loss of consciousness
  4. pale or blue lips, fingernails, or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Rare

  1. Increased in sexual ability, desire, drive, or performance
  2. increased interest in sexual intercourse

Incidence not known

  1. Cramps
  2. dizziness
  3. drowsiness
  4. heartburn
  5. hiccups
  6. increased hair growth, especially on the face
  7. loss of appetite
  8. nausea or vomiting
  9. nearsightedness
  10. pain or discomfort in the chest, upper stomach, or throat
  11. redness of the skin
  12. unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
  13. weight loss

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Portions of this document last updated: March 01, 2024

Original article: https://www.mayoclinic.org/drugs-supplements/ethosuximide-oral-route/description/drg-20072587