Maximum Daily Dose for Atomoxetine
The maximum recommended total daily dose of atomoxetine is 100 mg for all patients, or 1.4 mg/kg/day in children and adolescents, whichever is less. 1
Weight-Based Dosing Parameters
For Children and Adolescents ≤70 kg
- Maximum dose: 1.4 mg/kg/day or 100 mg daily, whichever is less 2, 1
- Target therapeutic dose: approximately 1.2 mg/kg/day 1
- Starting dose: approximately 0.5 mg/kg/day 1
For Children and Adolescents >70 kg and Adults
Important Safety Considerations
Doses above 100 mg daily have not been systematically evaluated for safety. 1 The FDA label specifically states that the safety of single doses over 120 mg and total daily doses above 150 mg have not been established. 1
Evidence Supporting Maximum Dose Limits
- Clinical trials demonstrated no additional therapeutic benefit for doses higher than 1.2 mg/kg/day in pediatric patients 1, 3
- In adults, doses of 60-120 mg/day were studied, with no data supporting increased effectiveness at higher doses 1, 4, 5
- The 1.8 mg/kg/day dose showed similar efficacy to 1.2 mg/kg/day without additional benefit 3
Special Population Adjustments
Hepatic Impairment
- Moderate hepatic impairment (Child-Pugh Class B): Reduce maximum dose to 50% of normal 1
- Severe hepatic impairment (Child-Pugh Class C): Reduce maximum dose to 25% of normal 1
CYP2D6 Poor Metabolizers or Strong Inhibitor Use
- For patients taking strong CYP2D6 inhibitors (paroxetine, fluoxetine, quinidine) or known poor metabolizers, the usual target dose of 1.2 mg/kg/day (pediatric) or 80 mg/day (adult) should only be reached if symptoms fail to improve after 4 weeks at lower doses and the initial dose is well tolerated 1
Critical Monitoring Requirements
Close monitoring for suicidality, clinical worsening, and unusual behavioral changes is essential, particularly during the first few months of treatment or with dose changes. 2 This black box warning applies regardless of the dose used. 6