ADULTS: Initially, 100-200 mg once or twice daily; slowly raise the dosage by increments of 100 to 200 mg every 2 weeks until an optimum response is obtained. In some patients 1600 mg or even 2000 mg daily may be appropriate. CHILDREN: For children aged 4 years or less, a starting dose of 20-60 mg/day,increasing by 20-60 mg every second day, has been recommended. For children over the age of 4 years, therapy may begin with 100 mg/day, increasing at weekly intervals by 100mg.