It is very important that your doctor check your progress at regular visits while you 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.
It is important to tell your doctor if you become pregnant while using this medicine. Your doctor may want you to join a pregnancy registry for patients taking a seizure medicine.
For some children, teenagers, and young adults, this medicine can increase thoughts of suicide. Tell your doctor or your child's doctor right away if you or your child start to feel more depressed or have thoughts about hurting yourself. Report any unusual thoughts or behaviors that trouble you or your child, especially if they are new or get worse quickly. Make sure the doctor knows if you or your child have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. Also tell the doctor if you or your child have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. Let the doctor know if you, your child, or anyone in your family has bipolar disorder (manic-depressive) or has tried to commit suicide.
Do not stop taking this medicine without first checking with your doctor. Your doctor may want you or your child to gradually reduce the amount you are using before stopping completely.
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. These could be a signs of a serious problem with the number of blood cells in your body.
Tell your doctor right away if you or your child has a skin rash, muscle or joint pain, feels unusually tired, has a low-grade fever, or pain the chest that gets worse with breathing. These could be signs of a serious condition called systematic lupus erythematosus (SLE).
Call your doctor right away if you or your child start to have a persistent cough, weight loss, night sweats, fever, chills, or flu-like symptoms such as a runny or stuffy nose, headache, blurred vision, or feeling generally ill. These may be signs that you have an infection.
Methsuximide may cause some people to become dizzy, drowsy, 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 not alert.