Skip to main content


Generic name: ethotoin [ ETH-oh-toyn ]
Brand name: Peganone
Dosage form: oral tablet (250 mg)
Drug class: Hydantoin anticonvulsants

What is ethotoin?

Ethotoin is an anti-epileptic medicine, also called an anticonvulsant.

Ethotoin is used alone or in combination with other medicines to treat seizures in adults and children who are at least 1 year old.

Ethotoin may also be used for purposes not listed in this medication guide.


You should not use ethotoin if you have liver disease or a blood cell disorder (such as anemia, hemophilia, and others).

Before taking this medicine

You should not use ethotoin if you are allergic to ethotoin or if you have:

  • liver disease; or

  • a blood cell disorder (such as anemia, hemophilia, and others).

To make sure ethotoin is safe for you, tell your doctor if you have:

Some people have thoughts about suicide while taking an anticonvulsant. Your doctor will need to check your progress at regular visits while you are taking ethotoin. Your family or other caregivers should also be alert to changes in your mood or symptoms.

FDA pregnancy category D. Do not start or stop taking ethotoin during pregnancy without your doctor's advice. Seizure control is very important during pregnancy. Ethotoin may cause harm to an unborn baby, but having a seizure during pregnancy could harm both mother and baby. Tell your doctor right away if you become pregnant while taking ethotoin for seizures.

There may be other seizure medicines that can be more safely used during pregnancy. Follow your doctor's instructions about taking this medicine while you are pregnant.

If you are pregnant, your name may be listed on a pregnancy registry. This is to track the outcome of the pregnancy and to evaluate any effects of ethotoin on the baby.

If you have taken ethotoin during pregnancy, be sure to tell the doctor who delivers your baby about your ethotoin use. Both you and the baby may need to receive medicine to prevent excessive bleeding during delivery and just after birth.

Ethotoin can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

How should I take ethotoin?

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

If you switch to ethotoin from taking another anti-epileptic medicine, do not stop taking the other medicine without your doctor's advice. Carefully follow your doctor's instructions about timing and dosage when switching from one seizure medicine to another.

Seizures are sometimes treated with a combination of drugs. Use all medicines as directed by your doctor. Read the medication guide or patient instructions provided with each medicine. Do not change your doses or medication schedule without your doctor's advice.

Take ethotoin after eating. Take your doses at regular intervals to keep a steady amount of the drug in your body at all times.

If a child is taking this medicine, tell your doctor if the child has any changes in weight. Ethotoin doses are based on weight in children.

Ethotoin can lower blood cells that help your body fight infections and help your blood to clot. You may get an infection or bleed more easily. Call your doctor if you have unusual bruising or bleeding, or signs of infection (fever, chills, sore throat).

While using ethotoin, you may need frequent blood and urine tests.

Do not stop using ethotoin suddenly, even if you feel fine. Stopping suddenly may cause increased seizures. Follow your doctor's instructions about tapering your dose.

Wear a medical alert tag or carry an ID card stating that you take ethotoin. Any medical care provider who treats you should know that you take seizure medicine.

Store at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include vision changes, nausea, extreme drowsiness, and trouble standing or walking.

What should I avoid while taking ethotoin?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Ethotoin side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, depression, anxiety, or if you feel agitated, hostile, irritable, restless, hyperactive (mentally or physically), or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have:

  • sudden weakness or ill feeling, fever, chills, sore throat, mouth sores, pain when swallowing, swollen glands, skin sores, cold or flu symptoms;

  • easy bruising or bleeding (nosebleeds, bleeding gums);

  • liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

  • lupus-like syndrome--joint pain or swelling, muscle pain, chest pain, shortness of breath, patchy skin color, swelling in your legs and feet; or

  • severe skin reaction--swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common side effects may include:

  • dizziness, tired feeling;

  • nausea or vomiting;

  • lack of balance or coordination;

  • double vision, jerky eye movements; or

  • changes in your gums.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect ethotoin?

Other drugs may interact with ethotoin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.