Recommended Dosage and Treatment Guidelines for Strattera (Atomoxetine) in ADHD
For patients with ADHD, atomoxetine (Strattera) should be initiated at 0.5 mg/kg/day and titrated after a minimum of 3 days to a target dose of 1.2 mg/kg/day, with a maximum recommended dose of 1.4 mg/kg/day or 100 mg daily, whichever is less. 1
Dosing Guidelines by Age and Weight
Children and Adolescents
- For children and adolescents up to 70 kg: Initial daily dose of 0.5 mg/kg, target total daily dose of 1.2 mg/kg, maximum daily dose of 1.4 mg/kg 2
- For children and adolescents over 70 kg: Initial daily dose of 40 mg, target total daily dose of 80 mg, maximum daily dose of 100 mg 2
- Atomoxetine can be administered either as a single daily dose or split into two evenly divided doses 3
- Titrate doses to achieve maximum benefit with minimum adverse effects 4
Adults
- Initial daily dose of 40 mg, target total daily dose of 80 mg, maximum daily dose of 100 mg 2, 5
- Can be administered once daily or split into two evenly divided doses 5
Age-Specific Treatment Recommendations
- For preschool-aged children (4-5 years): Atomoxetine is not recommended as it has not received sufficient rigorous study in this population 4, 1
- For elementary school-aged children (6-11 years): FDA-approved medications including atomoxetine may be prescribed along with parent/teacher-administered behavior therapy 4
- For adolescents (12-18 years): FDA-approved medications including atomoxetine may be prescribed with the adolescent's assent 4
Special Considerations for Dosing
- Dosing adjustments are necessary for patients with hepatic impairment, those taking strong CYP2D6 inhibitors, and patients known to be CYP2D6 poor metabolizers 2
- Poor metabolizers of CYP2D6 (approximately 7% of Caucasians) have plasma concentrations approximately 10-fold higher than extensive metabolizers 6
- Atomoxetine has a plasma half-life of 5.2 hours in extensive metabolizers and 21.6 hours in poor metabolizers 6
Safety Monitoring
- Monitor closely for suicidality, clinical worsening, and unusual behavior changes, especially during the first few months of treatment or with dose changes 1, 2
- Atomoxetine carries an FDA black box warning for increased risk of suicidal ideation in children and adolescents 2
- Monitor for adverse effects including decreased appetite, somnolence, gastrointestinal symptoms, and fatigue 1
- Perform cardiac evaluation if risk factors are present before starting treatment 1
- Monitor growth as atomoxetine has been linked to growth delays in the first 1-2 years of treatment 1
Efficacy and Therapeutic Considerations
- Atomoxetine is effective for ADHD but has a slower onset of action (2-4 weeks) compared to stimulants 7, 3
- Atomoxetine is particularly useful for patients at risk of substance abuse, as well as those who have co-morbid anxiety or tics 3, 8
- Atomoxetine has negligible risk of abuse or misuse and is not a controlled substance in the US 3, 5
- Atomoxetine is less effective than extended-release methylphenidate formulations and extended-release mixed amphetamine salts 3, 8
Administration Recommendations
- Atomoxetine can be administered as a single daily dose or split into two evenly divided doses 3
- Treatment effects are not usually observed until 2-4 weeks after initiation, unlike stimulants which have a more rapid onset 7
- Once-daily administration is typically recommended, with morning dosing often preferred 7
Common Adverse Effects
- Common adverse events include headache, abdominal pain, decreased appetite, vomiting, somnolence, and nausea 3
- Most adverse events are mild or moderate in severity 3
- Discontinuation of atomoxetine appears to be well tolerated, with a low incidence of discontinuation-emergent adverse events 3
By following these dosing guidelines and monitoring recommendations, clinicians can effectively use atomoxetine as part of a comprehensive treatment plan for patients with ADHD.