What is the recommended dosage of Strattera (atomoxetine) for an 8-year-old with Attention Deficit Hyperactivity Disorder (ADHD)?

Strattera Dosing for an 8-Year-Old with ADHD

For an 8-year-old with ADHD, start Strattera (atomoxetine) at 0.5 mg/kg/day for the first 3 days, then increase to approximately 1.2 mg/kg/day (target dose), with a maximum of 1.4 mg/kg/day or 100 mg/day, whichever is less. 1

Initial Dosing Strategy

For a child weighing approximately 25-30 kg (typical for an 8-year-old):

• Start with 0.5 mg/kg/day (approximately 12-15 mg daily) for the first 3 days to assess tolerability 2
• Increase to target dose of 1.2 mg/kg/day (approximately 30-36 mg daily) after initial tolerance is established 2
• Alternative adult-based approach: Begin at 40 mg once daily, though this may be higher than weight-based dosing for smaller children 1

The weight-based approach is more appropriate for an 8-year-old, as the 40 mg starting dose recommended by the American College of Obstetricians and Gynecologists is designed for adults and larger adolescents 1.

Titration Schedule

• Adjust dose every 7-14 days based on clinical response and tolerability 1
• Target therapeutic dose: 1.2 mg/kg/day, which has demonstrated optimal efficacy in clinical trials 2
• Maximum dose: 1.4 mg/kg/day or 100 mg/day, whichever is less 1
• Dosing frequency: Can be given once daily in the morning or split into two evenly divided doses 3

Timeline for Response

• Initial improvement: May be observed within 2 weeks of starting therapy 4
• Full therapeutic effect: Allow 6-12 weeks for complete response, as atomoxetine has a slower onset compared to stimulants 1
• Duration of action: Effects extend throughout waking hours and persist until the next morning with a single morning dose 2

Monitoring Requirements

During Initial Titration (First 6-12 weeks):

• Weekly contact during dose adjustments 1
• Systematically assess for side effects at each adjustment, particularly:
  • Gastrointestinal symptoms (nausea, decreased appetite) 2
  • Sleep disturbances 2
  • Mood changes and behavioral symptoms 5
  • Suicidality and clinical worsening (FDA black box warning applies) 5

After Dose Stabilization:

• Monthly follow-up appointments minimum 1
• Monitor weight at each visit to assess for appetite suppression 5
• Blood pressure and pulse monitoring, especially at higher doses 5

Common Pitfalls and Caveats

Avoid premature discontinuation: The most common mistake is stopping atomoxetine before 6-12 weeks, as full therapeutic effects take longer to manifest compared to stimulants 1. Many families expect immediate results similar to methylphenidate.

Side effects are typically transient: Gastrointestinal symptoms and decreased appetite are generally noted early in treatment and resolve over time 2. Reassure families while monitoring closely.

Consider alternative if inadequate response: If adequate symptom control is not achieved at maximum dose after 12 weeks, consider switching to stimulant medication or adding behavioral interventions 1.

Clinical Context for an 8-Year-Old

Atomoxetine is typically second-line after stimulants for ADHD treatment in children 1. However, it may be first-line in specific circumstances:

• Comorbid tic disorders or Tourette's syndrome 1
• Family preference for non-controlled substance due to negligible abuse potential 3
• Comorbid anxiety disorders (atomoxetine may provide additional benefit) 2
• Stimulant non-responders or those with intolerable stimulant side effects 3

Behavioral therapy should be integrated: The American Academy of Pediatrics recommends combining medication with behavioral interventions for optimal outcomes in school-aged children 5.

Practical Dosing Example

For a typical 8-year-old weighing 27 kg:

• Days 1-3: 13.5 mg once daily (0.5 mg/kg/day)
• Week 1-2: 32 mg once daily (1.2 mg/kg/day target dose)
• If needed after 2-4 weeks: Increase to 38 mg once daily (1.4 mg/kg/day maximum)
• Absolute maximum: 100 mg/day regardless of weight 1