Zarontin Side Effects

Generic name: ethosuximide

Medically reviewed by Drugs.com. Last updated on Sep 26, 2024.

Note: This document provides detailed information about Zarontin.

Applies to ethosuximide: oral capsule liquid filled, oral syrup Side Effects associated with ethosuximide. Some dosage forms listed on this page may not apply specifically to the brand name Zarontin.

Applies to ethosuximide: oral capsule liquid filled, oral syrup.

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 ethosuximide (the active ingredient contained in Zarontin) 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.

Serious side effects of Zarontin

Along with its needed effects, ethosuximide 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 while taking ethosuximide:

Rare side effects

• changes in behavior
• discouragement
• feeling sad or empty
• irritability
• lack of appetite
• loss of interest or pleasure
• mood or mental changes
• thoughts of killing oneself
• tiredness
• trouble with concentrating
• trouble with sleeping

Incidence not known

• bleeding gums
• blistering, peeling, or loosening of the skin
• blood in the urine
• bloody, black, or tarry stools
• chest pain
• cough or hoarseness
• diarrhea
• enlarged gums
• false or unusual sense of well-being
• fever with or without chills
• general feeling of discomfort or illness
• hair loss
• headaches
• high fever
• hives, itching, skin rash
• joint or muscle pain
• lower back or side pain
• nervousness
• not able to concentrate
• painful or difficult urination
• pale skin
• pinpoint red spots on the skin
• red skin lesions, often with a purple center
• red, irritated eyes
• restlessness
• shakiness and unsteady walk
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• swelling around the eyes
• swelling of the tongue
• swollen, painful, or tender lymph glands in the neck, armpit, or groin
• trouble sitting still
• trouble breathing
• unsteadiness, trembling, or other problems with muscle control or coordination
• unusual bleeding or bruising
• unusual tiredness or weakness
• vaginal bleeding
• vision changes
• yellow eyes or skin

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

Symptoms of overdose

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

Other side effects of Zarontin

Some side effects of ethosuximide 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 side effects

• increased in sexual ability, desire, drive, or performance
• increased interest in sexual intercourse

Incidence not known

• cramps
• dizziness
• drowsiness
• heartburn
• hiccups
• increased hair growth, especially on the face
• loss of appetite
• nausea or vomiting
• nearsightedness
• pain or discomfort in the chest, upper stomach, or throat
• redness of the skin
• unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
• weight loss

For healthcare professionals

Applies to ethosuximide: oral capsule, oral syrup.

General adverse events

The more commonly reported adverse reactions have included gastrointestinal symptoms such as anorexia, vague gastric upset, nausea and vomiting, and abdominal pain.

Gastrointestinal

• Frequency not reported: Anorexia, vague gastric upset, nausea, vomiting, cramps, epigastric and abdominal pain, weight loss, gum hypertrophy, diarrhea, swollen tongue, hiccups^[Ref]

Dermatologic

• Frequency not reported: Urticaria, Stevens-Johnson syndrome (SJS), pruritic erythematous rashes, hirsutism, Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), systemic lupus erythematosus^[Ref]

Hematologic

• Frequency not reported: Leukopenia, agranulocytosis, pancytopenia (with or without bone marrow suppression), eosinophilia, drug-induced immune thrombocytopenia^[Ref]

Nervous system

• Frequency not reported: Drowsiness, headache, dizziness, lethargy, fatigue, ataxia^[Ref]

Psychiatric

• Rare (less than 0.1%): Paranoid psychosis, increased libido, increased state of depression with overt suicidal intentions
• Frequency not reported: Disturbances, night terrors, inability to concentrate, aggressiveness, euphoria, irritability, hyperactivity^[Ref]

Ocular

• Frequency not reported: Myopia^[Ref]

Genitourinary

• Frequency not reported: Vaginal bleeding, microscopic hematuria^[Ref]

Hypersensitivity

• Frequency not reported: Allergic reaction

See also:

Further information

Zarontin side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer