Ethosuximide, Oral

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KEY POINTS

• This medicine is taken by mouth to control petit mal epilepsy. Take it exactly as directed. Carry some form of identification stating that you have seizures and are taking an antiseizure medicine.
• This medicine may increase suicidal thoughts or actions in some people.
• You may get infections more easily while taking this medicine. Keep all appointments for tests to see how this medicine affects you.
• This medicine may cause unwanted side effects, including a rash that may be a serious side effect. Tell your healthcare provider if you have any side effects that are serious, continue, or get worse.
• Tell all healthcare providers who treat you about all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take.

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What are other names for this medicine?

Type of medicine: antiseizure; succinimide

Generic and brand names: ethosuximide, oral; Zarontin

What is this medicine used for?

This medicine is used to control petit mal epilepsy, also called absence seizures. It may be used with other medicines.

This medicine may be used to treat other conditions as determined by your healthcare provider.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• An allergic reaction to any medicine
• Blood disorders such as anemia
• Depression or thoughts of suicide
• Kidney or liver disease
• Lupus

Females of childbearing age: Tell your healthcare provider if you are pregnant or breast-feeding. It is not known whether this medication will harm an unborn baby. Contact your healthcare provider right away if you become pregnant while taking this medicine. You and your healthcare provider should decide if you should continue taking this medicine while you are pregnant. Do not breast-feed while taking this medicine without your healthcare provider's approval.

How do I take it?

Read the Medication Guide that comes in the medicine package when you start taking this medicine and each time you get a refill.

Check the label on the medicine for directions about your specific dose. Take this medicine exactly as directed by your healthcare provider. Take it regularly to control your seizures. Do not change the dosage or stop taking this medicine without your healthcare provider's approval. Your seizures may get worse if you suddenly stop taking this medicine. You may have to gradually reduce your dosage.

Check with your healthcare provider before using this medicine in children under age 3.

If you have the liquid form of this medicine, use the measuring spoon, cup, dropper, or oral syringe that comes with the medicine, or ask your pharmacist for one. Do not use a kitchen spoon because the dose may not be correct.

You may take this medicine with or without food. Taking it with meals may lessen the chance the drug will upset your stomach.

What if I miss a dose?

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What if I overdose?

If you or anyone else has intentionally taken too much of this medicine, call 911 or go to the emergency room right away. If you pass out, have seizures, weakness or confusion, or have trouble breathing, call 911. If you think that you or anyone else may have taken too much of this medicine, call the poison control center. Do this even if there are no signs of discomfort or poisoning. The poison control center number is 800-222-1222.

Symptoms of an acute overdose may include: confusion, slurred speech, trouble walking, loss of balance, drowsiness, dizziness, lightheadedness, fainting, nausea, vomiting, slow or shallow breathing, coma.

What should I watch out for?

Antiseizure medicines may increase suicidal thoughts or actions in some people. Call your healthcare provider right away if you have new or increased depression, thoughts of suicide, or any unusual changes in mood or behavior.

You may get infections more easily while taking this medicine. Contact your healthcare provider right away if you have any signs of infection such as fever, chills, or sore throat. Also, contact your healthcare provider if you have unusual bruising or bleeding or unusual tiredness or weakness.

This medicine may cause serious side effects that can affect your liver or kidneys. Contact your healthcare provider right away if you have a fever, yellowing of the skin or eyes, dark urine, severe stomach pain, loss of appetite, unusual tiredness, unusual bruising or bleeding, or trouble urinating.

Tell your healthcare provider right away if you develop any rash while you are taking this medicine. A rash may be a symptom of a serious side effect.

You need to have blood tests regularly to see how this medicine affects you. Keep all appointments for these tests.

This medicine increases the effects of alcohol and other drugs that slow down your nervous system. Do not drink alcohol or take other medicines unless your healthcare provider approves.

This medicine may cause drowsiness, dizziness, or blurred vision. Do not drive or operate machinery unless you are fully alert.

If you need emergency care, surgery, lab tests, or dental work, tell the healthcare provider or dentist you are taking this medicine.

Carry some form of identification or a Medic Alert bracelet stating that you have seizures and are taking an antiseizure medicine. If you become unconscious, the ID tells emergency healthcare providers that you may need special care.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help.): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat).

Serious (Report these to your healthcare provider right away.): Increased number of seizures, chest pain, joint or muscle pain, fever, sore throat, cough, trouble breathing, swollen glands, unusual bruising or bleeding, unusual tiredness or weakness, blurred vision, thoughts of suicide, new or worsening depression, unusual thoughts or behavior, unexplained skin rash, blistering or peeling skin, mouth sores, problems with balance or walking, yellowing of the skin or eyes, dark urine, loss of appetite, severe stomach pain, severe nausea or vomiting, trouble urinating or decreased urination, confusion.

Other: Headache, mild nausea or vomiting, stomach cramps, hiccups, mild dizziness, drowsiness, trouble sleeping, bad dreams, diarrhea, weight loss.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• Antiviral medicines such as ombitasvir/paritaprevir/ritonavir/dasabuvir (Viekira), ombitasvir/paritaprevir/ritonavir (Technivie), and simeprevir (Olysio)
• Barbiturates such as butabarbital (Butisol), pentobarbital (Nembutal), phenobarbital, and secobarbital (Seconal)
• Bosentan (Tracleer)
• Cancer medicines such as ceritinib (Zykadia), crizotinib (Xalkori), dabrafenib (Tafinlar), enzalutamide (Xtandi), idelalisib (Zydelig), imatinib (Gleevec), mitotane (Lysodren), and nilotinib (Tasigna)
• Conivaptan (Vaprisol)
• Doxepin (Silenor)
• Flibanserin (Addyi)
• Heart medicines such as diltiazem (Cardizem, Cartia, Tiazac), dronedarone (Multaq), and verapamil (Calan, Covera, Verelan)
• HIV medicines such as atazanavir (Reyataz), cobicistat (Tybost), darunavir (Prezista), delavirdine (Rescriptor), efavirenz (Sustiva), elvitegravir/cobicistat/emtricitabine/tenofovir (Stribild), fosamprenavir (Lexiva), indinavir (Crixivan), lopinavir/ritonavir (Kaletra), nelfinavir (Viracept), nevirapine (Viramune), ritonavir (Norvir), and saquinavir (Invirase)
• Lumacaftor/ivacaftor (Orkambi)
• Mefloquine
• Mifepristone (Korlym, Mifeprex)
• Muscle relaxants such as baclofen (Gablofen, Lioresal), carisoprodol (Soma), cyclobenzaprine (Amrix), methocarbamol (Robaxin), and tizanidine (Zanaflex)
• Natural remedies such as evening primrose oil, ginkgo biloba, gotu kola, kava, St. John's wort, and valerian
• Nausea medicines such as aprepitant (Emend), prochlorperazine (Compro), and promethazine
• Orlistat (alli, Xenical)
• Other antiseizure medicines such as carbamazepine (Carbatrol, Epitol, Equetro, Tegretol), clobazam (Onfi), eslicarbazepine (Aptiom), felbamate (Felbatol), fosphenytoin (Cerebyx), lamotrigine (Lamictal), methsuximide (Celontin), oxcarbazepine (Trileptal), phenytoin (Dilantin, Phenytek), primidone (Mysoline), rufinamide (Banzel), topiramate (Qudexy, Topamax, Trokendi), valproic acid (Depacon, Depakene, Depakote), vigabatrin (Sabril), and zonisamide (Zonegran)
• Pain medicines such as codeine, fentanyl (Abstral, Actiq, Duragesic, Fentora, Sublimaze), hydrocodone (Hysingla, Zohydro), hydromorphone (Dilaudid, Exalgo), meperidine (Demerol), methadone (Dolophine, Methadose), morphine (Kadian, MS Contin), oxycodone (OxyContin, Roxicodone), oxycodone/acetaminophen (Percocet, Roxicet), pentazocine (Talwin), tapentadol (Nucynta), and tramadol (ConZip, Ultram)
• Paroxetine (Brisdelle, Paxil, Pexeva)
• Sleeping pills such as estazolam, eszopiclone (Lunesta), flurazepam, suvorexant (Belsomra), temazepam (Restoril), triazolam (Halcion), zaleplon (Sonata), and zolpidem (Ambien, Edluar, Intermezzo)
• Stimulants such as armodafinil (Nuvigil), dextroamphetamine (Dexedrine), methamphetamine (Desoxyn), and modafinil (Provigil)

Ask your healthcare provider or pharmacist if you need to avoid products that contain grapefruit, Seville oranges, and tangelos while you are taking this medicine. These fruits and juices can affect the way this medicine works and may increase your risk of serious side effects.

Do not drink alcohol while you are taking this medicine.

If you are not sure if your medicines might interact, ask your pharmacist or healthcare provider. Keep a list of all your medicines with you. List all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect from heat, high humidity, and bright light.

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This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.