Attention Deficit Hyperactivity Disorder

Huang and Shan, National Workshop of Clinical Use of Phenytoin, Chengdu, China (1992), 3137 studied a group of patients with attention deficit hyperactivity disorder (ADHD). They examined the therapeutic effects of phenytoin (50 mg tid for patients less than 10 years old and 100 mg tid for patients older than 10 years). As a comparison, the authors gave methylphenidate (10 mg/day for those under 10 years old and 10 mg bid for those over 10 years) and placebo (50 mg/day) in a randomized double-blind study (20 patients per group) of 60 children (48 boys and 12 girls, 7 - 12 years of age) with ADHD by DSM-IIIR criteria. Treatment duration was 4 weeks. Evaluation parameters included clinical response, abbreviated Connor's scale, Arabic number crossout test, EEG and parent-teacher reports. Serum phenytoin levels were also obtained.

Significant clinical improvement was observed in 13 of 20 (65%) phenytoin-treated patients, 15 of 20 (75%) with methylphenidate and 5 of 20 (25%) on placebo (P < 0.5). Mean scores on the Connor's scale decreased significantly with both phenytoin and methylphenidate, but not with placebo - the net score being the best in the phenytoin group (19.08 vs 14.48 for methylphenidate). Both phenytoin and methylphenidate improved restlessness, fidgeting, attention span and concentration. Parents commented that the children became more amenable to discipline, exhibited decreased restlessness, and did better in schoolwork. Three patients complained of side effects in the phenytoin group: irritability (1) and skin rashes (2). Eleven patients in the methylphenidate group had the following side effects: decreased appetite (4), insomnia (4), and irritability (3); and one patient in the placebo group had decreased appetite. The authors concluded that phenytoin is a useful drug in ADHD, with effectivness comparable to methylphenidate. Phenytoin has the advantage of being inexpensive, easy to use, readily available, and produces fewer side effects. Further studies over a longer treatment period are merited.

3137. Huang, M., Li, J., and Shan, Y. Effect of phenytoin in hyperactive children, Presented at the National Workshop of Clinical Use of Phenytoin, Chengdu, China (1992)

Huang, Li and Shan, Personal Communication, (1995), 3138 compared the therapeutic effects of phenytoin (PHT) to those of methylphenidate (MPH) and placebo in a randomized, double-blind study of 60 children (48 boys and 12 girls, ages 7 - 12) with attention deficit hyperactivity disorder (ADHD) as defined by DSM-III-R criteria. Treatment duration was 4 weeks. Evaluation parameters included clinical response, Abbreviated Conner's Scale, Arabic number crossout test, EEG, and parent-teacher reports. Serum phenytoin levels were also obtained. Significant clinical improvements were observed in 13 of 20 (65%) phenytoin-treated patients, 15 of 20 methylphenidate-treated patients (75%), and 5 of 20 (25%) treated with placebo. The effects of PHT and MPH were significantly better than those of placebo (X = 6.46, p < 0.005, and X = 10, p < 0.005) respectively. However, there was no significant difference between MPH and PHT (X = 0.48, p < 0.05). Both phenytoin and methylphenidate also improved scores on the Abbreviated Conner's scale compared to placebo, but the difference with placebo was not statistically significant. All three groups showed improvement on the Arabic crossout test. There was a tendency favoring phenytoin and methylphenidate. Separating the results of the clinical responders and non-responders further demonstrated the effectiveness of both phenytoin and methylphenidate, both with respect to net score and number of errors. Based on the data from their study, the authors conclude that phenytoin is a useful drug in ADHD, and that its effectiveness is comparable to that of methylphenidate.

Phenytoin has the advantage of being inexpensive, easy to use, readily available, and productive of fewer side effects. The authors recommend further studies over a longer treatment period in a much larger sample.

3138. Huang, M., Li, J., and Shan, Y., The effect of phenytoin on hyperactivity in children, Personal Communication, 1995.

Advisory