Strattera Pediatric Dosing
For children and adolescents with ADHD, initiate atomoxetine (Strattera) at 0.5 mg/kg/day and increase 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
Children and Adolescents ≤70 kg:
- Starting dose: 0.5 mg/kg/day
- Wait minimum 3 days, then increase to:
- Target dose: 1.2 mg/kg/day
- Maximum dose: 1.4 mg/kg/day or 100 mg/day (whichever is less)
- Administration: Can be given as single morning dose OR divided into morning and late afternoon/early evening doses 1
Children and Adolescents >70 kg:
- Starting dose: 40 mg/day
- Wait minimum 3 days, then increase to:
- Target dose: 80 mg/day
- After 2-4 additional weeks, may increase to:
- Maximum dose: 100 mg/day if optimal response not achieved 1
Evidence Supporting This Dosing
The FDA-approved dosing is strongly supported by dose-response studies. No additional benefit has been demonstrated for doses higher than 1.2 mg/kg/day 1. A 2024 dose-response meta-analysis of 12 trials involving 2,250 patients confirmed that efficacy increases up to 1.4 mg/kg/day, after which it plateaus 2. The pivotal dose-response study (Study 1) demonstrated that 1.8 mg/kg/day provided no additional benefit over 1.2 mg/kg/day, while 0.5 mg/kg/day was not superior to placebo 3.
Important Dosing Modifications
For CYP2D6 Poor Metabolizers or Strong Inhibitors:
If the child is taking strong CYP2D6 inhibitors (paroxetine, fluoxetine, quinidine) or is a known poor metabolizer:
- ≤70 kg: Start at 0.5 mg/kg/day, increase to 1.2 mg/kg/day only if symptoms don't improve after 4 weeks AND initial dose is well tolerated
- >70 kg: Start at 40 mg/day, increase to 80 mg/day only if symptoms don't improve after 4 weeks AND initial dose is well tolerated 1
For Hepatic Impairment:
- Moderate hepatic impairment (Child-Pugh B): Reduce initial and target doses to 50% of normal
- Severe hepatic impairment (Child-Pugh C): Reduce initial and target doses to 25% of normal 1
Critical Safety Monitoring
Before initiating atomoxetine, obtain personal and family cardiac history. If risk factors present, perform ECG and consider cardiology referral 4. Monitor closely for:
- Suicidal ideation (FDA black box warning): Especially during first few months and at dose changes 5
- Cardiovascular parameters: Heart rate and blood pressure (atomoxetine increases both) 4
- Growth parameters: Height and weight (growth delays may occur in first 1-2 years) 4
- Hepatotoxicity: Extremely rare but monitor for jaundice, dark urine, upper right quadrant tenderness 4
Common Adverse Effects
Most common side effects include nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence 5. To minimize gastrointestinal symptoms, avoid rapid dose escalation 4. If adverse effects are problematic, consider evening-only dosing 5.
Special Consideration: Comorbid ODD
Children with comorbid oppositional defiant disorder may require the higher end of the dosing range (1.8 mg/kg/day) for optimal response, whereas those without ODD typically respond adequately to 1.2 mg/kg/day 6.
Timeline for Response
Critical pitfall: Unlike stimulants, atomoxetine requires 6-12 weeks to achieve full therapeutic effect 5. Do not prematurely discontinue or escalate doses before allowing adequate time for response. Maintenance treatment has been demonstrated effective at doses of 1.2-1.8 mg/kg/day 1.
Practical Administration
- May be taken with or without food
- Capsules should be swallowed whole, not opened
- Can be discontinued without tapering 1