Strattera (Atomoxetine) Dosing for ADHD
Start atomoxetine at 40 mg once daily in adults and children over 70 kg, or 0.5 mg/kg/day in children and adolescents up to 70 kg, then titrate to a target dose of 80 mg daily (or 1.2 mg/kg/day) after a minimum of 3 days, with a maximum dose of 100 mg daily or 1.4 mg/kg/day, whichever is lower. 1
Initial Dosing by Body Weight
Children and adolescents up to 70 kg:
Children and adolescents over 70 kg and adults:
Titration Schedule
The FDA-approved titration involves increasing from 40 mg to the target of 80 mg after a minimum of 3 days, with further increases to 100 mg after at least 2-4 additional weeks if needed. 1
However, the American Academy of Child and Adolescent Psychiatry recommends slower titration at 1-2 week intervals to minimize behavioral activation and agitation, particularly in younger patients. 2 This approach involves:
- Maintaining the initial dose for at least 1-2 weeks before increasing 2
- Increasing by small increments (typically 10-25 mg) no more frequently than every 1-2 weeks 2
- Returning to the previous well-tolerated dose if side effects occur 2
Slow titration is generally better tolerated and helps avoid unintentionally exceeding the optimal dose. 2
Dosing Frequency
Atomoxetine can be administered as either a single morning dose or divided into two evenly split doses (morning and late afternoon/early evening). 1, 4 A single morning dose provides symptom control throughout the waking hours and into the next morning. 5, 4
Special Populations Requiring Dose Adjustment
CYP2D6 poor metabolizers and patients taking strong CYP2D6 inhibitors (like paroxetine, fluoxetine, quinidine):
- Start at 40 mg daily (or 0.5 mg/kg/day in children ≤70 kg) 1
- Only increase to 80 mg (or 1.2 mg/kg/day) after 4 weeks if symptoms fail to improve and the initial dose is well tolerated 1
- Approximately 7% of the population are poor metabolizers with significantly higher plasma levels and longer half-lives 3
Hepatic impairment:
- Moderate impairment (Child-Pugh Class B): Reduce to 50% of normal dose 1
- Severe impairment (Child-Pugh Class C): Reduce to 25% of normal dose 1
Critical Safety Monitoring
All patients must be monitored closely for suicidal ideation, clinical worsening, and unusual behavioral changes, especially during the first few months of treatment or at times of dose changes. 2, 3, 1 This is particularly important given the FDA black box warning for increased risk of suicidal ideation in children and adolescents. 1
Monitor for behavioral activation/agitation (motor or mental restlessness, insomnia, impulsiveness, talkativeness, disinhibited behavior, aggression), which can occur early in treatment or with dose increases. 2 Younger patients are more susceptible to these effects with rapid dose escalation. 2
Baseline and ongoing monitoring should include:
- Blood pressure and heart rate at each visit 1
- Height and weight in pediatric patients 1
- Liver function if jaundice or symptoms of liver injury develop 1
- Cardiovascular assessment before initiating treatment 1
Timeline to Therapeutic Effect
Set appropriate expectations: atomoxetine requires 6-12 weeks to achieve full therapeutic effect, unlike stimulants which work within hours. 2 This delayed response timeline is essential to communicate to patients and families to prevent premature discontinuation. 2
Common Pitfalls to Avoid
Do not increase doses too rapidly. Rapid escalation increases the risk of behavioral activation, agitation, and other adverse effects, particularly in younger patients. 2
Do not discontinue atomoxetine in patients with jaundice or laboratory evidence of liver injury—it should not be restarted. 1
Do not use atomoxetine within 2 weeks of discontinuing an MAOI or in patients with narrow-angle glaucoma, pheochromocytoma, or severe cardiovascular disorders. 1
Screen all patients for bipolar disorder before initiating treatment, as atomoxetine may precipitate manic episodes. 1