Strattera (Atomoxetine) 40mg Daily Dosing
For patients currently on 40mg daily, this represents the standard starting dose for adults and adolescents over 70kg, and should be maintained for a minimum of 3 days before considering any dose increase. 1
Initial Dosing and Titration Schedule
- Start at 40mg once daily (single morning dose or divided into morning and late afternoon/evening doses) for adults and patients over 70kg 1
- Maintain this initial 40mg dose for at least 3 days before increasing to assess tolerability 1
- After the minimum 3-day period, increase to the target dose of 80mg daily (either as single morning dose or divided doses) 1
- Wait an additional 2-4 weeks at 80mg before considering further increases 1
- Maximum dose is 100mg daily for adults and adolescents over 70kg 1
Critical Timing Considerations
- Allow 1-2 weeks at each dose level to properly assess tolerability before increasing, as recommended by the American Academy of Child and Adolescent Psychiatry 2
- Full therapeutic effect requires 6-12 weeks, unlike stimulants which work within hours—set appropriate patient expectations 2
- Increasing doses too rapidly risks behavioral activation/agitation (motor restlessness, insomnia, impulsiveness, aggression), particularly in younger patients 2
Dosing Adjustments for Special Circumstances
When taking CYP2D6 inhibitors (paroxetine, fluoxetine, quinidine, duloxetine):
- Maintain 40mg for 4 weeks minimum before increasing 1
- Only increase to 80mg if symptoms fail to improve AND the initial dose is well tolerated 1
- These medications significantly increase atomoxetine exposure and half-life 3
Hepatic impairment:
- Moderate impairment (Child-Pugh Class B): Reduce all doses to 50% of normal 1
- Severe impairment (Child-Pugh Class C): Reduce all doses to 25% of normal 1
Administration Guidelines
- Can be taken with or without food 1
- Single daily dosing is as effective as divided dosing and may improve adherence 4
- Swallow capsules whole—do not open or crush 1
- Can be discontinued without tapering 1
Monitoring Requirements
- Measure blood pressure and heart rate at baseline, after each dose adjustment, and at least monthly during maintenance 2, 3
- Monitor for suicidality closely during the first few months and at times of dose changes (FDA black box warning) 2, 5
- Watch for hepatic symptoms (abdominal pain, jaundice, elevated transaminases)—discontinue immediately if these occur 3
- Monitor for behavioral activation especially in the first 24-48 hours after dose changes 6
Common Adverse Effects to Anticipate
- Gastrointestinal effects (nausea, vomiting, abdominal pain) are most common and typically transient 2, 7
- Decreased appetite and initial weight loss may occur 2
- Somnolence and fatigue can occur, particularly if dose is increased too rapidly 2
- Cardiovascular changes (modest increases in heart rate and blood pressure) are generally well tolerated 5
Key Clinical Pitfalls to Avoid
- Do not exceed 100mg daily—no data support increased effectiveness at higher doses 1
- Do not increase doses more frequently than every 1-2 weeks—this increases risk of behavioral activation 2
- If side effects occur, return to the previous well-tolerated dose rather than discontinuing entirely 2
- Do not expect immediate results—counsel patients that full effect takes 6-12 weeks 2