What is the recommended starting dose for Straterra (atomoxetine)?

Starting Dose for Strattera (Atomoxetine)

For children and adolescents up to 70 kg, initiate Strattera at approximately 0.5 mg/kg/day total daily dose, and for those over 70 kg and adults, start at 40 mg/day. 1

Weight-Based Dosing Algorithm

Patients ≤70 kg (Children and Adolescents)

• Initial dose: 0.5 mg/kg/day total daily dose 1
• Can be administered as a single morning dose OR divided into morning and late afternoon/early evening doses 1
• Wait a minimum of 3 days before increasing to target dose 1
• Target dose: 1.2 mg/kg/day (reached after minimum 3 days) 1
• Maximum dose: 1.4 mg/kg/day or 100 mg daily, whichever is less 1

Patients >70 kg (Adolescents and Adults)

• Initial dose: 40 mg/day total daily dose 1
• Can be administered as a single morning dose OR divided into morning and late afternoon/early evening doses 1
• Wait a minimum of 3 days before increasing to target dose 1
• Target dose: 80 mg/day (reached after minimum 3 days) 1
• After 2-4 additional weeks at 80 mg, may increase to maximum of 100 mg if optimal response not achieved 1
• Maximum dose: 100 mg/day 1

Critical Dosing Adjustments

Hepatic Impairment

• Moderate hepatic insufficiency (Child-Pugh Class B): Reduce initial and target doses to 50% of normal dose 1
• Severe hepatic insufficiency (Child-Pugh Class C): Reduce initial and target doses to 25% of normal dose 1

CYP2D6 Poor Metabolizers or Strong CYP2D6 Inhibitor Use

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

• Patients ≤70 kg: Start at 0.5 mg/kg/day, increase to usual target of 1.2 mg/kg/day only if symptoms fail to improve after 4 weeks and initial dose is well tolerated 1
• Patients >70 kg: Start at 40 mg/day, increase to usual target of 80 mg/day only if symptoms fail to improve after 4 weeks and initial dose is well tolerated 1

Important Titration Principles

Slow, gradual dose escalation is essential to minimize adverse effects and avoid behavioral activation. 2

• Maintain initial dose for at least 1-2 weeks before considering dose increases 2
• Increase by small increments (typically 10-25 mg) no more frequently than every 1-2 weeks 2
• Behavioral activation (agitation, restlessness, insomnia, impulsiveness, aggression) can occur early in treatment or with dose increases, particularly in younger patients 2
• If side effects occur, consider returning to the previous well-tolerated dose 2

Key Safety Considerations Before Initiating

• Screen for bipolar disorder: Assess personal or family history of bipolar disorder, mania, or hypomania before starting atomoxetine 1
• Monitor for suicidality: Close monitoring is required for suicidal ideation, clinical worsening, and unusual behavioral changes, especially during the first few months or with dose changes 2
• Set realistic expectations: Atomoxetine requires 6-12 weeks to achieve full therapeutic effect, unlike stimulants which work within hours 2

Administration Details

• May be taken with or without food 1
• Capsules should be swallowed whole, not opened 1
• Can be discontinued without tapering 1
• Single doses over 120 mg and total daily doses above 150 mg have not been systematically evaluated for safety 1

Common Pitfalls to Avoid

• Do not escalate too rapidly: This increases risk of behavioral activation, nausea, vomiting, decreased appetite, and other gastrointestinal side effects 2, 3, 4
• Do not expect immediate response: Unlike stimulants, full therapeutic benefit takes 6-12 weeks 2
• Do not forget CYP2D6 interactions: Failure to adjust dosing when using strong CYP2D6 inhibitors can lead to significantly increased exposure and adverse effects 1, 3
• Do not exceed maximum doses: No additional benefit demonstrated at doses higher than 1.2 mg/kg/day in children or 100 mg/day in adults 1