Methsuximide is an anti-epileptic medication, also called an anticonvulsant.

Methsuximide is used alone or in combination with other medications to treat absence seizures (also called "petit mal" seizures) in adults and children.

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

Serious and sometimes fatal infections may occur during treatment with methsuximide. Call your doctor right away if you have signs of infection such as: fever, swollen glands, sore throat, easy bruising, unusual bleeding (nose, mouth), feeling very weak or tired.

Do not stop using methsuximide suddenly. Stopping suddenly may cause increased seizures.

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

Methsuximide can weaken your immune system. Your blood may need to be tested often.

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

Call your doctor if your seizures get worse or you have them more often while taking methsuximide.

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

Use methsuximide regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

Store at room temperature away from moisture and heat. Do not allow liquid medicine to freeze.

Usual Adult Dose for Seizures:

Initial dose: 300 mg orally once a day for the first week
-If needed, increase the daily dosage in increments of 300 mg/day at weekly intervals
Maximum dose: 1200 mg/day

Comments:
-The above dosing is suggested, however, because therapeutic effect and tolerance may vary among patients, therapy must be individualized according to the response of each patient.
-The optimal dose is the amount of drug which is barely sufficient to control seizures so that side effects may be kept to a minimum.

Use: For the control of absence (petit mal) seizures that are refractory to other drugs.

Usual Pediatric Dose for Seizures:

Children:
Initial dose: 10 to 15 mg/kg/day orally in 3 to 4 divided doses
-May increase at weekly intervals
Maximum dose: 30 mg/kg/day

Comments:
-The above dosing is suggested, however, because therapeutic effect and tolerance may vary among patients, therapy must be individualized according to the response of each patient.
-The optimal dose is the amount of drug which is barely sufficient to control seizures so that side effects may be kept to a minimum.

Use: For the control of absence (petit mal) seizures that are refractory to other drugs.

You should not use methsuximide if you are allergic to methsuximide or to other seizure medications.

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

• lupus;

• liver disease;

• kidney disease; or

• a history of depression, mood problems, or suicidal thoughts or actions.

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

Follow your doctor's instructions about taking seizure medication if you are pregnant. Do not start or stop taking this medicine without your doctor's advice, and tell your doctor right away if you become pregnant. Methsuximide may cause harm to an unborn baby, but having a seizure during pregnancy could harm both mother and baby. The benefit of preventing seizures may outweigh any risks to the baby.

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 methsuximide on the baby.

It is not known whether methsuximide passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

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.

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

Overdose symptoms may include nausea, vomiting, extreme drowsiness, and weak or shallow breathing.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature, away from light, excess heat, and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unless your doctor tells you otherwise, continue your normal diet.

Drinking alcohol with methsuximide can cause side effects.

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Get emergency medical help if you have 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, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), depressed, or have thoughts about suicide or hurting yourself.

Serious and sometimes fatal infections may occur during treatment with methsuximide. Call your doctor right away if you have signs of infection such as:

• fever;

• swollen glands, sore throat;

• easy bruising, unusual bleeding (nose, mouth); or

• feeling very weak or tired.

Also call your doctor at once if you have:

• confusion, hallucinations, unusual thoughts or behavior, extreme fear;

• worsening seizures;

• lupus-like syndrome--joint pain or swelling with fever, swollen glands, muscle aches, chest pain, vomiting, unusual thoughts or behavior, and patchy skin color; or

• severe skin reaction--fever, sore throat, 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 of methsuximide may include:

• nausea, vomiting, stomach pain, loss of appetite;

• diarrhea, constipation;

• weight loss;

• headache, dizziness, drowsiness;

• blurred vision; or

• loss of balance or coordination.

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.

Taking this medicine with other drugs that make you dizzy or sleepy can worsen this effect. Ask your doctor before taking methsuximide with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Tell your doctor about all your current seizure medications, and any you start or stop using.

Other drugs may interact with methsuximide, 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.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to methsuximide.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.