Risperidone Metabolism in Children and Adolescents

More and more children and adolescents are taking psychiatric medications every year. Although these medications can help children who suffer with mental disorders, they can also have side effects. These side effects vary from the relatively minor, such as dry mouth, to the very serious yet rare, such as permanent movement disability (tardive dyskinesia) or even death. Despite the seriousness of this situation, the effects and side effects of medications in children have not been thoroughly studied. We are proposing to study the genetic variation of a major breakdown enzyme (named Cytochrome P450 2D6) in children and adolescents. This enzyme is involved in the breakdown of many antipsychotic and antidepressant medications, including risperidone. Risperidone is being prescribed for children and adolescents who have been diagnosed with Schizophrenia, Conduct Disorder, ADHD, Tic Disorder, and Autism. Preliminary studies in our laboratory on adults show that people who do not have this enzyme (possibly up to 7% of the population), so-called poor metabolizers, are more likely to have side effects from risperidone. We plan to study up to three hundred children and adolescents who are currently on risperidone or who have been on it in the past. It is our hope that this information may lead to a better understanding of how side effects may relate to how children and adolescents break down medication. This may possibly lead to new physician guidelines that would promote screening of a child's breakdown genetics and thus prevent serious and life-threatening side effects.