RISPERIDONE IN PATIENTS WITH AUTISTIC BEHAVIORAL PROBLEMS

Objectives: Since recent medications for violent behaviors including autistic behavior are effectively used for adult patients, however not extensively for child patients, the introduction of better medications into pediatric field is necessary.

Methods: Twenty four children (1–15 ys) and 11 adult patients of severe intellectual disabilities with autistic behavior such as communication problems, sleep disturbance, short attention span, repulsion, self-injuries, aggression, hyperkinetic, were treated with risperidone gradually increased in an amount of 10–50 microgram/kg at out-patient clinic. As an atypical antipsychotic agent, risperidone is allowed only for adult patients with schizophrenia in Japan, every patient involved in this study was obtained of informed consent after an in detailed explanation of the effectiveness and safety of the drug. Diagnosis and changes of the patients was estimated after follow-up study for 2–3 year by DMS-IV for doctors and autism diagnostic interview-revised (ADI-R) by Lord C et al (1994) for mothers and care-givers.

Results: Improvement of violent behavior was noticed partially in 20/24 for children and 12/12 for adult. Sleep disturbance is improved in almost all patients used before bed at night. Seizures were found in 7 children who were treated with anticonvulsants such as valproate-Na which showed some effects to violent behavior also, however three cases showed serotonin syndrome caused probably by valproate-Na together with risperidone.

Conclusions: In this study, risperidone, a potent antagonist of central serotonin and dopamine receptors, was more or less effective in all cases for violent behaviors. However, 30% of risperidone treated children (7/24) showed seizures, being necessary for antiepileptic drug. The value is identical to the incidence of epilepsy in autism. Furthermore, both of the drugs increases brain serotonin level, which may cause serotonin syndrome.