What is the recommended dosing for Strattera (atomoxetine) in adults?

Strattera (Atomoxetine) Adult Dosing

For adults, initiate Strattera at 40 mg once daily and increase after a minimum of 3 days to a target dose of 80 mg daily, administered either as a single morning dose or divided into morning and late afternoon/evening doses, with a maximum of 100 mg daily. 1

Initial Dosing

• Start at 40 mg once daily for all adults and adolescents over 70 kg body weight 1
• Maintain this initial dose for at least 3 days before any dose increase 1
• Can be taken with or without food 1

Target Dosing

• Increase to 80 mg daily after the minimum 3-day period at 40 mg 1
• This 80 mg dose can be given as:
  • Single morning dose, OR
  • Divided into two doses (morning and late afternoon/evening) 1
• After 2-4 additional weeks at 80 mg, may increase to maximum of 100 mg daily in patients without optimal response 1

Maximum Dose

• 100 mg per day is the maximum recommended dose for adults 1
• No data support increased effectiveness at doses higher than 100 mg 1
• Single doses over 120 mg and total daily doses above 150 mg have not been systematically evaluated for safety 1

Dosing Adjustments for Specific Populations

CYP2D6 Poor Metabolizers or Concurrent Strong CYP2D6 Inhibitors

When taking strong CYP2D6 inhibitors (paroxetine, fluoxetine, quinidine) or in known CYP2D6 poor metabolizers:

• Start at 40 mg daily (same as standard) 1
• Only increase to 80 mg after 4 weeks if symptoms fail to improve AND initial dose is well tolerated 1
• This adjustment is critical because CYP2D6 inhibition increases atomoxetine plasma concentrations approximately 10-fold, converting extensive metabolizers to a poor metabolizer phenotype 2, 3

Hepatic Impairment

• Moderate hepatic impairment (Child-Pugh Class B): Reduce initial and target doses to 50% of normal (start 20 mg, target 40 mg) 1
• Severe hepatic impairment (Child-Pugh Class C): Reduce initial and target doses to 25% of normal (start 10 mg, target 20 mg) 1

Titration Principles

• Increase doses gradually at 1-2 week intervals to optimize tolerability 4
• Slow titration helps avoid exceeding the optimal dose and reduces risk of behavioral activation (restlessness, insomnia, impulsiveness, agitation) that can occur with rapid dose escalation 4
• If side effects occur, return to the previous well-tolerated dose 4

Time to Therapeutic Effect

• Full therapeutic effect requires 6-12 weeks, unlike stimulants which work within hours 4
• Set appropriate patient expectations about this delayed response timeline 4
• Maintain patients on target dose for adequate duration before concluding treatment failure 4

Maintenance Treatment

• Atomoxetine can be discontinued without tapering 1
• Periodically reevaluate long-term usefulness for individual patients 1
• Symptoms typically return upon discontinuation 4

Safety Monitoring

• Monitor closely for suicidality, clinical worsening, and unusual behavioral changes, especially during the first few months or at dose changes 4
• Screen for personal or family history of bipolar disorder, mania, or hypomania before initiating treatment 1

Common Adverse Effects

The most frequent adverse events in adults include dry mouth, insomnia, nausea, decreased appetite, constipation, dizziness, sweating, dysuria, sexual problems, and palpitations 5, 6

Clinical Efficacy Data

In controlled 10-week trials, atomoxetine at doses of 60-120 mg/day produced mean reductions in ADHD symptom scores of 28-30% versus 18-20% with placebo 5, 6