What is the recommended dosage of atomoxetine (Strattera) for treating attention deficit hyperactivity disorder (ADHD)?

Atomoxetine (Strattera) Dosing for ADHD

The recommended dosage of atomoxetine for ADHD is 0.5 mg/kg/day as a starting dose, titrated to a target dose of 1.2 mg/kg/day for optimal therapeutic effect. 1

Dosing Guidelines by Age Group

Children and Adolescents (≤70 kg)

• Initial dose: 0.5 mg/kg/day
• Target dose: 1.2 mg/kg/day
• Maximum dose: 1.8 mg/kg/day (though 1.2 mg/kg/day is generally as effective as 1.8 mg/kg/day) 1, 2
• Can be administered as a single morning dose or divided into morning and late afternoon doses 3

Adults and Children >70 kg

• Initial dose: Begin with 40 mg/day
• Target dose: 80 mg/day
• Maximum dose: 100 mg/day
• Doses should be titrated after a minimum of 3 days 1, 3

Clinical Evidence Supporting Dosing Recommendations

Clinical studies have demonstrated a graded dose-response relationship with atomoxetine:

• The 0.5 mg/kg/day dose shows some efficacy but is generally inferior to higher doses 2
• The 1.2 mg/kg/day dose demonstrates robust efficacy in symptom reduction 3, 2
• The 1.8 mg/kg/day dose does not provide significant additional benefit over 1.2 mg/kg/day 3, 2

In FDA clinical trials, atomoxetine at doses of 1.2-1.8 mg/kg/day was consistently superior to placebo in reducing ADHD symptoms and improving social and family functioning 3.

Administration Considerations

• Timing options:

  • Once-daily dosing in the morning has proven effective 3
  • Divided dosing (morning and late afternoon/evening) is also effective 3

• Titration: Gradually increase from starting dose to target dose over several weeks to minimize side effects 1

• Duration before assessing efficacy: Unlike stimulants, atomoxetine requires 4-6 weeks at target dose for full therapeutic effect 4

Special Considerations

• Maintenance treatment: Some patients may maintain response at lower doses (0.5 mg/kg/day) during long-term maintenance, which can reduce side effects 5

• Underdosing concern: Real-world data suggests many adult patients receive suboptimal dosing (average ~60 mg/day vs. recommended 80 mg/day), potentially compromising efficacy 4

• Clinical pearls:

  • Lower doses (0.3 mg/kg) may optimize cognitive performance
  • Higher doses (1.0 mg/kg) may better control behavioral symptoms 1
  • Monitoring for diminishing effects over time is important 1

Monitoring Recommendations

• Follow-up within 2-4 weeks after medication initiation 1
• Regular assessment of:
  • ADHD symptoms using standardized scales
  • Blood pressure and heart rate
  • Side effects (particularly gastrointestinal symptoms, which are most common)
  • Suicidal ideation, especially when initiating therapy in young adults 1

Drug Interactions

• Avoid combination with: Monoamine oxidase inhibitors due to risk of serotonin syndrome 1
• Use caution with medications that reduce blood pressure 1

Atomoxetine is a non-stimulant option particularly valuable for patients with substance use disorders (due to lower abuse potential) or mood vulnerabilities 1.