Maximum Recommended Dose of Strattera (Atomoxetine)
The maximum recommended dose of Strattera is the lesser of 1.4 mg/kg/day or 100 mg/day, whichever is lower. 1, 2, 3
Dosing Algorithm by Patient Weight and Age
Adults and Children Over 70 kg
- Starting dose: 40 mg orally once daily 1, 4
- Titration schedule: Increase dose every 7-14 days to 60 mg, then 80 mg daily 1
- Maximum dose: 100 mg/day (regardless of weight) 1, 2, 3
Children and Adolescents Up to 70 kg
- Starting dose: Approximately 0.5 mg/kg/day 4
- Target dose: 1.2 mg/kg/day 5, 6
- Maximum dose: 1.4 mg/kg/day or 100 mg/day, whichever is less 1, 2, 3
Critical Dosing Principles
Never exceed 100 mg/day total, even if the weight-based calculation (1.4 mg/kg) would suggest a higher dose. 1, 2, 3 This absolute ceiling exists regardless of patient size or response.
Titration Guidelines to Avoid Common Pitfalls
- Increase dose in the smallest available increments at 1-2 week intervals to assess tolerability before advancing 4
- Maintain each dose level for at least 1-2 weeks before increasing 4
- Typical increment size: 10-25 mg per adjustment 4
- If side effects occur, return to the previous well-tolerated dose rather than pushing through 4
Why Slow Titration Matters
Rapid dose escalation significantly increases risk of behavioral activation, including motor restlessness, insomnia, impulsiveness, aggression, and disinhibited behavior 4. Younger patients are particularly susceptible to these effects with rapid increases 4.
Time to Full Therapeutic Effect
Atomoxetine requires 6-12 weeks to achieve full therapeutic effect, unlike stimulants which work within days 2, 4. Set appropriate expectations with patients about this delayed response timeline to prevent premature dose escalation or discontinuation 2, 4.
Special Population Considerations
Renal Insufficiency
Atomoxetine can be administered using the normal dosing regimen in patients with end-stage renal disease or lesser degrees of renal insufficiency, as systemic exposure corrected for mg/kg dose shows no significant difference 3.
Poor Metabolizers (CYP2D6)
No specific dose adjustment is provided in guidelines, but these patients may require lower doses due to higher systemic exposure 3. Poor metabolizers are more common in Caucasians 3.
Safety Monitoring Requirements
- Monitor closely for suicidality, clinical worsening, and unusual behavioral changes, especially during the first few months or with dose changes 4, 3
- Obtain baseline and monitor blood pressure, heart rate, height, and weight at follow-up visits 4
- Common adverse effects include nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence 4, 3
Clinical Response Expectations
At the target dose of 1.2 mg/kg/day, atomoxetine reduces ADHD symptoms by 34-38% versus 13-15.7% with placebo 4. In adults receiving 60-120 mg/day, mean reductions in ADHD symptom scores range from 28-30% versus 18-20% with placebo 7, 8.