The best amount is the amount that completely controls seizures without causing troublesome side effects. It depends on many factors, which are different for every individual. Follow the doctor's directions. Call if you have any questions.

Zonisamide is usually started at 100 to 200 milligrams per day (mg) for adults. For children, the amount is calculated according to child's weight. Children usually start at 2 to 4 mg per kilogram (kg, about 2.2 pounds) per day, divided into two doses.

Dosages should be increased at 2-week intervals to an ongoing dose of 400 to 600 mg per day for adults and 4 to 8 mg per kg per day for children. Some people may need (and be able to tolerate) higher dosages.