Minimum Age for Prescribing Risperidone
According to FDA labeling, risperidone is approved for use in children as young as 5 years of age for the treatment of irritability associated with autistic disorder. 1
FDA-Approved Indications by Age Group
Risperidone has specific age-based approvals for different conditions:
- Autism Spectrum Disorder (irritability): 5-16 years
- Bipolar I Disorder: 10-17 years
- Schizophrenia: 13-17 years
Evidence Base for Autism Spectrum Disorder
The FDA approval for risperidone in autism is based on two 8-week, placebo-controlled trials in children and adolescents aged 5-16 years who met DSM-IV criteria for autistic disorder 1. Over 90% of these subjects were under 12 years of age. The medication demonstrated significant improvement in:
- Irritability subscale of the Aberrant Behavior Checklist (ABC-I)
- Clinical Global Impression-Change (CGI-C) scale
In these studies, risperidone was administered at doses of 0.5-3.5 mg/day on a weight-adjusted basis, with a mean modal dose of approximately 1.9 mg/day (equivalent to 0.06 mg/kg/day) 1.
Dosing Considerations
For children with autism spectrum disorder:
- Starting dose: 0.25 mg/day for children <20 kg; 0.5 mg/day for children ≥20 kg
- Titration: Gradual increase based on response and tolerability
- Typical effective dose range: 0.5-3.5 mg/day or 0.02-0.06 mg/kg/day 2
Important Safety Considerations
When prescribing risperidone to children aged 5 years and older, monitor for:
Weight gain: In short-term trials, mean weight gain was 2.7 kg with risperidone versus 0.8 kg with placebo 3. In longer-term studies, mean weight gain was 5.1 kg over 4 months 4.
Somnolence: Occurs in up to 74% of children, typically early in treatment with a median duration of 16 days 1, 5.
Metabolic effects: Monitor for hyperglycemia and lipid abnormalities.
Prolactin elevation: May occur even without clinical symptoms 6.
Extrapyramidal symptoms: Including tardive dyskinesia (rare in children, 0.1% in clinical trials) 1.
Long-Term Considerations
Efficacy appears to be maintained for at least 6 months in approximately two-thirds of initial responders 3, 4. However, discontinuation after 6 months of treatment is associated with high relapse rates (62.5% with placebo substitution vs. 12.5% with continued risperidone) 4, 7.
Key Takeaways
- Risperidone should not be prescribed to children under 5 years of age as safety and efficacy have not been established in this population.
- For children 5 years and older, risperidone is FDA-approved specifically for irritability associated with autism spectrum disorder.
- Weight-based dosing and careful monitoring for side effects are essential when prescribing to pediatric populations.
- The risk-benefit profile should be carefully evaluated, with particular attention to metabolic effects and weight gain with long-term use.