Atomoxetine Treatment for Children with ADHD
Atomoxetine 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 for children with ADHD, with careful monitoring for side effects including suicidal ideation, somnolence, and decreased appetite. 1
Dosing Protocol
Initial Dosing
- For children up to 70 kg: Start at 0.5 mg/kg/day 1
- For children over 70 kg: Start at 40 mg/day 1
- May be administered as a single morning dose or divided into morning and late afternoon doses 1
Titration
- Increase after minimum of 3 days to target dose of 1.2 mg/kg/day for children up to 70 kg 1
- Increase to 80 mg/day for children over 70 kg 1
- Maximum daily dose: 1.4 mg/kg or 100 mg (whichever is less) 1
- No additional benefit demonstrated for doses higher than 1.2 mg/kg/day 1
Monitoring and Side Effects
Common Side Effects
- Initial somnolence and gastrointestinal symptoms (particularly if dosage increased too rapidly) 2
- Decreased appetite 2
- Headache, abdominal pain, vomiting, and nausea 3
Serious Concerns Requiring Monitoring
- Suicidal ideation (FDA black box warning) - monitor closely, especially during first few months of treatment 2
- Rare hepatitis - monitor liver function 2
- Growth delays - typically returns to expected trajectory after 2-3 years 2
- Cardiac effects - perform ECG if risk factors present 2
Clinical Positioning
When to Consider Atomoxetine as First-Line
- History of substance abuse concerns 4
- Significant anxiety comorbidity 4
- Tic disorders or Tourette's syndrome 4
- Patient/family preference to avoid controlled substances 4, 5
Efficacy Considerations
- Less effective than extended-release methylphenidate and mixed amphetamine salts 3, 5
- Similar efficacy to immediate-release methylphenidate 3, 5
- Shows graded dose-response with 1.2 mg/kg/day being as effective as 1.8 mg/kg/day 6
- Effective for both inattentive and hyperactive/impulsive symptoms 6
Special Populations
Preschool Children (4-5 years)
- No nonstimulant medication has received sufficient rigorous study in preschool-aged children to be recommended 2
- Methylphenidate is the recommended first-line pharmacologic treatment for this age group 2
CYP2D6 Poor Metabolizers
- Initiate at 0.5 mg/kg/day and only increase to target dose if symptoms fail to improve after 4 weeks 1
- More likely to experience adverse effects 3
Hepatic Impairment
- Moderate impairment: Reduce initial and target doses to 50% of normal 1
- Severe impairment: Reduce initial and target doses to 25% of normal 1
Adjunctive Therapy
- Limited evidence supports using atomoxetine in combination with stimulant medications to augment treatment 2
- Extended-release guanfacine and extended-release clonidine have FDA approval as adjunctive therapy with stimulants 2
Long-term Management
- Periodically reevaluate the long-term usefulness of the medication 1
- Can be discontinued without tapering 1
- May be taken with or without food 1
- Capsules should be taken whole, not opened 1
Atomoxetine offers a valuable non-stimulant option for ADHD treatment with particular advantages for specific patient populations, though it generally shows less efficacy than stimulant medications. Careful monitoring, especially during initiation and dose adjustments, is essential to manage potential side effects and ensure optimal outcomes.