What is the youngest age at which Buspar (buspirone) can be prescribed?

Minimum Age for Buspirone Prescription

Buspirone is FDA-approved for use in patients 18 years and older, and should not be prescribed to children under this age for anxiety disorders.

FDA Approval Status and Evidence

The FDA drug label for buspirone clearly states that safety and effectiveness were evaluated in pediatric trials involving patients aged 6-17 years with Generalized Anxiety Disorder (GAD), but the results did not show significant differences between buspirone and placebo for treating GAD symptoms 1. These clinical trials failed to demonstrate efficacy in the pediatric population despite adequate dosing.

Two large randomized controlled trials specifically examining buspirone in pediatric patients with GAD found:

• In a fixed-dose trial (N=341) and a flexibly dosed trial (N=227), buspirone did not separate from placebo in improving anxiety symptoms 2
• These trials were underpowered to detect small effect sizes (Cohen's d < 0.15) 2

Pharmacokinetic Considerations

Pharmacokinetic studies have shown that for identical doses, plasma exposure to buspirone and its active metabolite (1-PP) are equal to or higher in pediatric patients than adults 1. This indicates that the lack of efficacy was not due to inadequate dosing or absorption issues.

Safety Concerns

While buspirone has a generally favorable safety profile compared to other anxiolytics:

• Dropout rates due to treatment-emergent adverse events were significantly higher in buspirone-treated pediatric patients compared to placebo (p=0.011) 2
• Common side effects in pediatric trials included lightheadedness (occurring significantly more frequently than placebo, p<0.001) 2
• Buspirone is metabolized by the liver and excreted by the kidneys, with impaired function in either organ resulting in increased plasma levels and lengthened half-life 1

Limited Off-Label Evidence

Some limited retrospective evidence suggests potential benefit in specific populations:

• A retrospective chart review of high-functioning autism spectrum disorder youth with anxiety (ages 8-17) showed some improvement with buspirone treatment 3, but this was not a controlled trial and cannot override the negative findings from properly controlled studies

Practical Guidance

For clinicians considering anxiety treatment in pediatric patients:

1. For patients under 18 years: Buspirone is not recommended based on lack of demonstrated efficacy in controlled trials
2. For patients 18 years and older: Standard adult dosing applies (typically starting at 7.5 mg twice daily, increasing to 15-30 mg daily in divided doses)
3. Alternative treatments with established efficacy in pediatric anxiety should be considered instead

Conclusion

Based on the available evidence, particularly the FDA drug label and controlled clinical trials, buspirone should only be prescribed to patients 18 years and older. The lack of demonstrated efficacy in pediatric anxiety disorders, despite adequate evaluation in clinical trials, does not support its use in younger populations.