Atomoxetine (Strattera) Dosing for Teenagers
For teenagers, atomoxetine (Strattera) should be initiated at 0.5 mg/kg/day and increased after a minimum of 3 days to a target dose of 1.2 mg/kg/day, with a maximum of 1.4 mg/kg/day or 100 mg daily (whichever is less). 1
Weight-Based Dosing Algorithm
For teens weighing up to 70 kg:
- Initial dose: 0.5 mg/kg/day
- Target dose: 1.2 mg/kg/day (after minimum 3 days)
- Maximum dose: 1.4 mg/kg/day or 100 mg daily (whichever is less)
For teens weighing over 70 kg:
- Initial dose: 40 mg daily
- Target dose: 80 mg daily (after minimum 3 days)
- Maximum dose: 100 mg daily
Administration Options
Atomoxetine can be administered in one of two ways:
- As a single daily dose in the morning
- As evenly divided doses in the morning and late afternoon/early evening
The medication should be taken whole (not opened) and can be administered with or without food 1.
Special Dosing Considerations
Hepatic Impairment
- Moderate hepatic impairment: Reduce dose to 50% of normal dose
- Severe hepatic impairment: Reduce dose to 25% of normal dose 2, 1
CYP2D6 Poor Metabolizers or Patients Taking CYP2D6 Inhibitors
- For teens up to 70 kg: Start at 0.5 mg/kg/day and only increase to target dose if symptoms don't improve after 4 weeks
- For teens over 70 kg: Start at 40 mg/day and only increase to 80 mg/day if symptoms don't improve after 4 weeks 1
Monitoring Parameters
Vital signs: Blood pressure and heart rate should be monitored at each visit, as atomoxetine can cause modest increases in both parameters 3, 4
Growth: Height and weight should be monitored regularly, as there may be an initial decrease in expected growth that typically normalizes with continued treatment 3
Mental health status: Screen for suicidal ideation, as atomoxetine carries a black box warning for increased risk of suicidal thinking in children and adolescents 3
Liver function: Monitor for signs of liver injury, which has been rarely reported with atomoxetine use 3
Common Side Effects
The most common adverse effects include:
Clinical Advantages
Atomoxetine has several advantages over stimulant medications:
- Not classified as a controlled substance
- Negligible risk of abuse or misuse
- Can be particularly useful for teens with comorbid anxiety or tic disorders
- Effects last throughout the day with once-daily dosing 3, 5
Important Precautions
- Screen for bipolar disorder before initiating treatment 1
- Monitor for signs of liver injury, though this is rare
- Be aware of potential drug interactions, particularly with strong CYP2D6 inhibitors like fluoxetine or paroxetine 1, 6
Atomoxetine has demonstrated efficacy in treating ADHD symptoms in adolescents, with improvements in both core ADHD symptoms and quality of life measures 3, 5.