What is the recommended dosage of atomoxetine (Strattera) for children with Attention Deficit Hyperactivity Disorder (ADHD)?

Recommended Dosage of Atomoxetine for Children with ADHD

For children with ADHD, atomoxetine should be initiated at 0.5 mg/kg/day and titrated after a minimum of 3 days to a target dose of 1.2 mg/kg/day, with a maximum recommended dose of 1.4 mg/kg/day or 100 mg daily, whichever is less. 1, 2

Weight-Based Dosing Recommendations

Children and adolescents up to 70 kg:

• Start with 0.5 mg/kg/day 2
• Increase after minimum of 3 days to target dose of 1.2 mg/kg/day 2
• Maximum dose: 1.4 mg/kg/day or 100 mg daily, whichever is less 1, 2
• Can be administered as a single morning dose or divided into morning and late afternoon doses 2

Children and adolescents over 70 kg:

• Start with 40 mg/day 2
• Increase after minimum of 3 days to target dose of 80 mg/day 2
• Maximum dose: 100 mg daily 2
• Can be administered as a single morning dose or divided into morning and late afternoon doses 2

Administration Considerations

• Atomoxetine can be taken with or without food 2
• Capsules should be taken whole, not opened 2
• Once-daily morning dosing has been shown to provide symptom relief throughout the day, including evening and early morning hours 3
• No additional benefit has been demonstrated for doses higher than 1.2 mg/kg/day 2

Special Dosing Considerations

For patients with hepatic impairment:

• Moderate hepatic impairment (Child-Pugh Class B): Reduce initial and target doses to 50% of normal dose 2
• Severe hepatic impairment (Child-Pugh Class C): Reduce initial and target doses to 25% of normal dose 2

For CYP2D6 poor metabolizers or patients taking CYP2D6 inhibitors:

• For children ≤70 kg: Start at 0.5 mg/kg/day and only increase to 1.2 mg/kg/day if needed after 4 weeks 2
• For children >70 kg: Start at 40 mg/day and only increase to 80 mg/day if needed after 4 weeks 2
• Approximately 7% of the population are poor metabolizers of atomoxetine, with higher plasma levels and longer half-lives 1

Safety Monitoring

• Monitor closely for suicidality, clinical worsening, and unusual behavior changes, especially during the first few months of treatment or with dose changes 1
• Monitor for adverse effects including decreased appetite, somnolence, gastrointestinal symptoms, and fatigue 1
• Perform cardiac evaluation if risk factors are present before starting treatment 1
• Monitor growth as atomoxetine has been linked to growth delays in the first 1-2 years of treatment 1

Treatment Duration and Reassessment

• Periodically reevaluate the long-term usefulness of atomoxetine for the individual patient 2
• The benefit of maintaining pediatric patients on atomoxetine has been demonstrated in controlled trials 2

Important Cautions

• Atomoxetine carries an FDA black box warning for increased risk of suicidal ideation in children and adolescents 1
• Screen for bipolar disorder prior to initiating treatment 2
• Atomoxetine is not recommended for preschool-aged children (under 6 years) as it has not received sufficient rigorous study in this population 1
• While one retrospective study suggests atomoxetine may be well-tolerated in 3-6 year-olds with comorbid ASD and ADHD, this is not an FDA-approved indication 4