What is the recommended treatment and dosage of Atomoxetine (Strattera) for Attention Deficit Hyperactivity Disorder (ADHD)?

Atomoxetine Treatment for ADHD

Atomoxetine is recommended at a starting dose of 0.5 mg/kg/day for children and adolescents up to 70 kg or 40 mg/day for those over 70 kg and adults, titrated to a target dose of 1.2 mg/kg/day (maximum 1.4 mg/kg/day or 100 mg/day, whichever is lower). 1, 2

Dosing and Administration

• Atomoxetine can be administered as a single daily dose or divided into two evenly divided doses (morning and evening) 3, 4
• Titration should follow a sequential, weight-based approach with dose adjustments typically made every 7-14 days 1
• For children and adolescents up to 70 kg: start with 0.5 mg/kg/day, target 1.2 mg/kg/day, maximum 1.4 mg/kg/day 1, 2
• For individuals over 70 kg and adults: start with 40 mg/day, target 80 mg/day, maximum 100 mg/day 2
• Therapeutic effects may take 6-12 weeks to fully manifest, unlike stimulants which work more rapidly 1, 3

Efficacy and Clinical Evidence

• Atomoxetine is FDA-approved for ADHD treatment in children, adolescents, and adults 1
• Clinical trials demonstrated significant improvement in ADHD symptoms compared to placebo, with mean reductions in ADHD symptom scores of 28-30% versus 18-20% for placebo 4, 5
• Atomoxetine provides "around-the-clock" symptom control without the peaks and valleys associated with stimulant medications 1, 3
• The 1.2 mg/kg/day dose has been shown to be as effective as 1.8 mg/kg/day in reducing ADHD symptoms, suggesting this is the appropriate target dose for most patients 6

Positioning in Treatment Algorithm

• Stimulants are generally recommended as first-line therapy for ADHD due to their larger effect sizes 3
• Atomoxetine is positioned as a second-line therapy in many European countries but is approved as first-line in the United States 1, 3
• Atomoxetine may be considered as first-line in specific situations:
  • Patients with comorbid substance use disorders 1
  • Patients with tic disorders or Tourette's syndrome 1
  • Patients with sleep disturbances that might be exacerbated by stimulants 3
  • When continuous 24-hour coverage is needed 3

Monitoring and Safety Considerations

• FDA Black Box Warning: Increased risk of suicidal ideation in children and adolescents; patients should be monitored closely, especially during the first few months of treatment or with dose changes 1, 2
• Common adverse effects include:
  • Decreased appetite, nausea, vomiting, fatigue, and abdominal pain 1
  • Headache, somnolence, and dizziness 1, 4
• Monitor vital signs regularly, as atomoxetine can cause modest increases in heart rate and blood pressure 2, 4
• Monitor height and weight in pediatric patients as growth effects may occur 2
• Atomoxetine is metabolized through CYP2D6; dose adjustments may be needed for poor metabolizers or when used with CYP2D6 inhibitors 1, 2

Special Considerations

• Atomoxetine is not a controlled substance and has negligible risk of abuse or diversion, making it advantageous for patients with substance use concerns 4, 5
• Contraindicated in patients with:
  • Narrow-angle glaucoma 2
  • Use within 2 weeks of MAOIs 2
  • Pheochromocytoma or history of pheochromocytoma 2
  • Severe cardiovascular disorders 2
• Use with caution in patients with hypertension, tachycardia, or cardiovascular disease 2

Clinical Pearls

• Atomoxetine's full therapeutic effects may take 6-12 weeks to develop, requiring patience during initial treatment 1, 3
• If switching from stimulants, be aware that patients may perceive less immediate benefit due to atomoxetine's more gradual onset of action 3
• The 1.2 mg/kg/day dose appears to be the optimal target dose for most patients, with limited additional benefit at higher doses 6
• Consider split dosing initially to reduce side effects, with the option to transition to once-daily dosing later 3