Can atomoxetine be dosed in 10mg increments?

Atomoxetine Dosing in 10mg Increments

Yes, atomoxetine can be dosed in 10mg increments, as it is manufactured in capsules containing 10,18,25,40,60,80, and 100 mg of atomoxetine hydrochloride. 1

Available Formulations

Atomoxetine is available in the following forms:

• Capsules: 10,18,25,40,60,80, and 100 mg
• Oral solution: 4 mg/ml 1

Dosing Guidelines

Initial Dosing

• For children and adolescents up to 70 kg: Start with 0.5 mg/kg/day 2
• For adults and children over 70 kg: Start with 40 mg daily 2

Dose Titration

• Doses can be increased after a minimum of 3 days 2
• Target dose is 1.2 mg/kg/day for children and adolescents up to 70 kg 2
• Target dose is 80 mg daily for adults and children over 70 kg 2
• Maximum dose should not exceed 1.4 mg/kg/day or 100 mg daily, whichever is lower 1, 2

Titration Schedule

A typical dose progression using 10mg increments might look like:

• Week 1: 10mg or 20mg daily (depending on weight)
• Week 2: 20mg or 30mg daily
• Week 3: 30mg or 40mg daily
• Week 4: 40mg daily
• Week 5: 50mg daily
• Week 6: 60mg daily

For higher doses, the standard available capsule strengths would be used (60mg, 80mg, 100mg).

Special Populations

Poor CYP2D6 Metabolizers

• Approximately 7% of the population are poor CYP2D6 metabolizers 2, 3
• These individuals may require lower doses due to slower clearance of atomoxetine 2
• Poor metabolizers have approximately 10-fold higher average steady-state plasma concentrations compared to extensive metabolizers 3

Hepatic Impairment

• For moderate hepatic impairment (Child-Pugh Class B): Reduce initial and target doses to 50% of normal dose 2
• For severe hepatic impairment (Child-Pugh Class C): Reduce doses to 25% of normal dose 2

Duration of Treatment

• An adequate trial requires at least 4 weeks at the target dose before judging efficacy 2
• Some patients may need 4-6 weeks to see full benefits 2
• For maintenance treatment, a lower dose of 0.5 mg/kg/day may be effective after initial response to higher doses 4

Monitoring

• Weekly contact during initial dose titration is recommended 2
• Monitor for common side effects, particularly:
  • Gastrointestinal effects (nausea, vomiting, decreased appetite) 1, 5
  • Cardiovascular effects (slight increases in heart rate and blood pressure) 5
  • Suicidal ideation, especially during the first few months or with dose changes 1, 2

Clinical Considerations

• Atomoxetine has a negligible risk of abuse or misuse and is not a controlled substance 5
• Unlike stimulants, atomoxetine provides 24-hour symptom control 2
• Atomoxetine may be particularly useful for patients with:
  • Risk of substance abuse 5, 6
  • Comorbid anxiety or tics 5
  • Need for continuous symptom control throughout the day 2

Practical Dosing Tips

• Atomoxetine can be administered either as a single daily dose or split into two evenly divided doses 5
• When using 10mg increments for precise dosing, capsules can be combined (e.g., 10mg + 18mg = 28mg total daily dose)
• For patients who need doses between available capsule strengths, the oral solution (4 mg/ml) provides more flexible dosing options 1

Remember that while atomoxetine can be dosed in 10mg increments using the available formulations, the standard practice is to follow weight-based dosing to achieve optimal therapeutic effects with minimal side effects.