Since Mysoline must be introduced gradually, the doctor will start by giving the patient a low dose. Here is an example of a typical schedule for building up to the desired level of Mysoline for an older child or adult:

Days 1 to 3: 100 to 125 mg at bedtime
Days 4 to 6: 100 to 125 mg each morning and evening
Days 7 to 9: 100 to 125 mg morning, noon, and night
Days 10 and later: 250 mg morning, noon, and night

Patients aged 8 or older usually take one 250-mg Mysoline tablet three or four times a day to maintain control of their seizures. Some people need to take more tablets, but the total dose should not exceed 2000 mg per day.

For children under 8 years of age, the usual dose for controlling seizures is 125 to 250 mg three times daily. The doctor may calculate the dose according to the child's weight, based on 10 to 25 mg of Mysoline per day for each kilogram (about 2.2 pounds) of the child's weight. Here is an example of a schedule that may be used to start a young child on Mysoline:

Days 1 to 3: 50 mg at bedtime
Days 4 to 6: 50 mg morning and evening.
Days 7 to 9: 100 mg morning and evening
Days 10 and later: 125 mg three times a day to 250 mg three times a day

Be sure to use only the amount that the doctor prescribes. If you think you've taken one or two extra tablets, call your doctor for advice. For a larger overdose, call your local poison control center or emergency room right away.

No one should stop taking Mysoline or change the amount they take without talking to the doctor first. Stopping any seizure medicine all at once can cause a serious condition called status epilepticus.

Reviewed February 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.