What are the considerations for increasing the dosage of Strattera (atomoxetine) in a patient currently taking 40mg twice a day (BID) for Attention Deficit Hyperactivity Disorder (ADHD)?

Increasing Strattera (Atomoxetine) from 40mg BID

Your patient is currently taking 80mg total daily dose (40mg BID), which is already at the FDA-recommended target dose for adults; increase to 100mg total daily (the maximum recommended dose) only if symptoms have not achieved optimal response after 2-4 weeks at 80mg. 1

Current Dosing Status

• Your patient is taking 40mg twice daily = 80mg total daily dose 1
• According to FDA labeling, for adults and adolescents >70kg, atomoxetine should be initiated at 40mg total daily and increased after a minimum of 3 days to a target of 80mg daily 1
• Your patient is already at the standard target dose 1

Criteria for Dose Increase

Increase to 100mg total daily only if:

• The patient has been at 80mg daily for at least 2-4 additional weeks 1
• Symptoms have not achieved optimal response at 80mg 1
• The current dose is well tolerated without significant adverse effects 1

Maximum Dosing Parameters

• The absolute maximum recommended total daily dose is 100mg for adults and adolescents >70kg 1
• There are no data supporting increased effectiveness at doses higher than the target range 1
• The safety of total daily doses above 150mg has not been systematically evaluated 1

Dosing Schedule Options

• The 100mg total daily dose can be administered either as a single morning dose or split into evenly divided doses (morning and late afternoon/early evening) 1
• If increasing from 40mg BID, consider either 50mg BID or 100mg once daily 1

Monitoring During Dose Increase

Cardiovascular monitoring is essential:

• Monitor heart rate and blood pressure regularly, as atomoxetine can increase HR and BP 2
• Obtain detailed cardiac history and family history of sudden death, cardiovascular symptoms, or cardiac conditions before any dose increase 2

Watch for psychiatric adverse effects:

• Monitor for agitation, irritability, hostility, impulsivity, restlessness, or mania, particularly in the first 24-48 hours after dose changes 2
• Screen for personal or family history of bipolar disorder before increasing dose 1
• Be aware of the FDA black box warning for suicidal ideation, which may emerge with dose changes 3

Common adverse effects to monitor:

• Decreased appetite, nausea, dry mouth, insomnia, constipation, and dizziness 3, 4
• Initial somnolence and gastrointestinal symptoms can occur, particularly if dose is increased too rapidly 2

Special Considerations Before Increasing

Check for CYP2D6 interactions:

• If the patient is taking strong CYP2D6 inhibitors (paroxetine, fluoxetine, quinidine), the dose should only be increased to 80mg if symptoms fail to improve after 4 weeks and the initial dose is well tolerated 1
• Poor CYP2D6 metabolizers have greater exposure and slower elimination of atomoxetine 3

Hepatic function:

• Ensure the patient does not have hepatic insufficiency, which would require dose reduction rather than increase 1

Timeline for Response Assessment

• The median time to response (25% improvement in ADHD symptoms) is 3.7 weeks 5
• The probability of symptom improvement may continue to increase up to 52 weeks after treatment initiation 5
• Do not increase the dose prematurely—allow at least 2-4 weeks at 80mg before considering an increase to 100mg 1

Common Pitfall to Avoid

Do not exceed 100mg total daily dose. The FDA labeling explicitly states there are no data supporting increased effectiveness at higher doses, and the maximum recommended dose is 100mg 1. Pushing beyond this increases adverse effect risk without demonstrated benefit 3.