Strattera (Atomoxetine) Dosage Increase from 40mg Daily
After starting at 40mg daily, increase Strattera to 80mg daily after a minimum of 3 days, with the option to further increase to a maximum of 100mg daily after an additional 2-4 weeks if needed. 1
Standard Titration Schedule
For patients over 70kg (including most adults):
- Start: 40mg daily
- After minimum 3 days: Increase to 80mg daily (target dose)
- After 2-4 additional weeks at 80mg: May increase to 100mg daily maximum if response is suboptimal 1
The 80mg dose can be given either as a single morning dose or split into two divided doses (morning and late afternoon/early evening). 1
Important Timing Considerations
Wait at least 1-2 weeks at each dose before increasing to properly assess tolerability and avoid behavioral activation (restlessness, agitation, impulsiveness, aggression), which is more likely with rapid dose escalation. 2 Younger patients are particularly susceptible to these activation symptoms with rushed titration. 2
Full therapeutic effect requires 6-12 weeks, so do not judge efficacy prematurely or increase doses too quickly seeking immediate response. 2, 3 This is fundamentally different from stimulants which work within hours. 2
Dosage Adjustments for Special Circumstances
If taking CYP2D6 inhibitors (fluoxetine, paroxetine, quinidine):
- Start at 40mg daily
- Increase to 80mg only after 4 weeks if symptoms fail to improve AND the initial dose is well tolerated
- Consider maximum dose of 60-80mg rather than 100mg due to significantly elevated atomoxetine levels 1, 3
With hepatic impairment:
- Moderate impairment: Reduce all doses to 50% of normal
- Severe impairment: Reduce all doses to 25% of normal 1
Critical Safety Monitoring
Monitor at each dose increase:
- Blood pressure and heart rate (atomoxetine can cause modest increases) 2, 3
- Suicidal ideation, especially in first few months and with dose changes 2
- Gastrointestinal symptoms (nausea, vomiting, abdominal pain, decreased appetite) 2, 4
- Behavioral activation/agitation 2
Common Pitfalls to Avoid
- Do not increase faster than every 3 days minimum (and preferably wait 1-2 weeks) to avoid intolerable side effects and behavioral activation 1, 2
- Do not exceed 100mg daily as there is no data supporting increased effectiveness at higher doses 1
- Do not judge efficacy before 6-8 weeks at target dose, as atomoxetine has delayed onset unlike stimulants 2, 3
- Do not ignore drug interactions with CYP2D6 inhibitors which dramatically increase atomoxetine levels 1, 3