Strattera (Atomoxetine) Onset of Effects
Strattera requires 6-12 weeks to achieve full therapeutic effects, which is substantially longer than stimulant medications that work within hours. 1
Timeline for Noticing Effects
Initial Response Period
- Some improvement may be noticed within 3 months of starting treatment at the optimal dose of 1.2 mg/kg/day, with marked or moderately pronounced clinical effects observed in approximately 78% of patients by this timepoint 2
- Full therapeutic benefit takes 6-12 weeks to develop, requiring patience during the initial treatment phase 1, 3
- This delayed onset is a key distinguishing feature from stimulants like methylphenidate, which produce effects within 2 hours of administration 4
What to Expect During Titration
- Start at 0.5 mg/kg/day (or 40 mg/day for patients over 70 kg and adults), then titrate to the target dose of 1.2 mg/kg/day over 7-14 day intervals 1
- Maximum dose is 1.4 mg/kg/day or 100 mg/day, whichever is lower 1
- Daily compliance is essential throughout this period, as inconsistent dosing will delay therapeutic effects 3
Clinical Monitoring Strategy
Assessment Schedule
- Schedule follow-up at 6-12 weeks to properly assess treatment response, as earlier assessments may not capture full efficacy 1
- Use standardized rating scales (ADHD-RS, CAARS) to objectively measure symptom improvement 5, 6
- Monitor vital signs (blood pressure and heart rate) at each visit, as modest increases can occur 1, 6
Common Side Effects to Anticipate
- Gastrointestinal symptoms and decreased appetite are the most common adverse effects, typically transient in nature 5
- Headache, somnolence, nausea, and abdominal pain may occur early in treatment 1
- In adults, additional side effects include dry mouth, insomnia, constipation, dizziness, and sexual problems 6, 7
Important Clinical Considerations
Advantages of Delayed-Onset Profile
- Provides 24-hour "around-the-clock" symptom coverage without the peaks and valleys of stimulant medications 1, 5
- No rebound symptoms when doses wear off or upon discontinuation 5
- No abuse potential, making it particularly useful for patients with substance use concerns 6, 7
When to Consider Alternatives
- If no response after 12 weeks at optimal dosing, consider switching to stimulant medications (methylphenidate or amphetamine derivatives) which have larger effect sizes 1
- Alternative non-stimulants include extended-release guanfacine or clonidine 1
- Stimulants remain first-line therapy due to superior efficacy, with atomoxetine positioned as second-line treatment 1
Critical Safety Warning
- FDA Black Box Warning for suicidal ideation in children and adolescents requires close monitoring, especially during the first few months of treatment or with dose changes 1