Can I increase atomoxetine (Strattera) from 40mg to 80mg daily after 5 days?

Atomoxetine Dose Titration from 40mg to 80mg

No, you should not increase atomoxetine from 40mg to 80mg after only 5 days of treatment; the FDA-approved titration schedule recommends waiting a minimum of 3 weeks before dose increases. 1

Proper Atomoxetine Titration Schedule

Atomoxetine (Strattera) requires a more gradual titration schedule than many other medications to minimize side effects and optimize therapeutic response:

• Initial dose: 40mg daily for adults and children over 70kg 1
• Titration period: Minimum of 3 days before increasing dose 1
• Target dose: Approximately 80mg daily 1
• Evaluation period: 2-4 additional weeks at target dose before considering further increases 1, 2
• Maximum dose: 100mg daily (no evidence supports increased effectiveness at higher doses) 1

Rationale for Longer Titration Period

Rushing the titration process can lead to several negative outcomes:

• Increased side effects: Rapid dose escalation increases risk of adverse events such as dry mouth, nausea, and decreased appetite 3
• Reduced tolerability: Discontinuation due to adverse events is more common with faster titration 3
• Suboptimal assessment: The full therapeutic effect of atomoxetine may take 4-6 weeks to manifest 4

Optimal Dosing Approach

For best results, follow this algorithm:

1. Start with 40mg daily for at least 3 days (preferably 1-2 weeks)
2. If well tolerated, increase to 80mg daily (either as a single morning dose or divided into morning and late afternoon doses) 1
3. Maintain the 80mg dose for 2-4 weeks before assessing full effectiveness 1
4. If response is inadequate after 2-4 weeks at 80mg, consider increasing to maximum 100mg daily 1

Special Considerations

• Hepatic impairment: For moderate hepatic impairment (Child-Pugh Class B), reduce initial and target doses to 50% of normal; for severe impairment (Child-Pugh Class C), reduce to 25% of normal 1
• CYP2D6 poor metabolizers: If you are taking CYP2D6 inhibitors (e.g., paroxetine, fluoxetine) or are a known poor metabolizer, maintain the 40mg dose for at least 4 weeks before considering an increase 1

Monitoring During Titration

• Schedule follow-up within 2-4 weeks after any dose change 2
• Monitor for common side effects: dry mouth, nausea, decreased appetite, insomnia 3, 5
• Be alert for cardiovascular effects: modest increases in heart rate and blood pressure can occur 5

Atomoxetine's full therapeutic benefit may take several weeks to manifest, so patience with the titration process is essential for optimal outcomes and minimizing side effects.