A new study from Thailand indicates that the antipsychotic medication risperidone (Risperdal) has frequent side effects when given to children with autism spectrum disorder. The side effects are mostly "mild and tolerable," the researchers note, but many of the children gained weight while on the drug, which they found "concerning."
The investigators studied 45 children in 2006 and 2007 with ASD aged two to 15 who were being treated for behaviors associated with ASD. (Risperidone is approved by the Food and Drug Administration for irritability in children with ASD.) They obtained information by interviewing parents and reviewing medical records. Length of treatment ranged from 27.8 to 36.8 months.
The doses of risperidone used ranged from 0.74 mg to 0.94 mg per day. (The recommended dose is based on weight, and ranges from 0.25 mg to 3 mg per day.) Side effects occurred in 39 children (86.7 percent). The most common side effects included:
- increased appetite
- runny nose
None of the children experienced a condition called "tardive dyskinesia" -- a neurological disorder that causes involuntary movements of the face and jaw and may occur with antipsychotic medications.
The children's weight gain was 2.2 to 4.18 kg (about six to nine pounds) a year, which the researchers say "exceeded developmentally expected norms."
"The results from this study suggest that risperidone treatment in children with ASD is associated with frequent mild and tolerable adverse effects," they note. "However, excessive weight gain could be found to be a concerning adverse effect and weight monitoring is warranted when risperidone is being prescribed."