What is the proper dosage and administration of Strattera (atomoxetine) for Attention Deficit Hyperactivity Disorder (ADHD)?

Proper Dosage and Administration of Strattera (Atomoxetine) for ADHD

For the treatment of ADHD, Strattera (atomoxetine) should be dosed based on weight, with initial doses of 0.5 mg/kg/day for children/adolescents up to 70 kg and 40 mg/day for those over 70 kg and adults, titrating to target doses of 1.2 mg/kg/day and 80 mg/day respectively, with maximum doses of 1.4 mg/kg/day and 100 mg/day. 1

Weight-Based Dosing Guidelines

For Children and Adolescents up to 70 kg:

• Initial daily dose: 0.5 mg/kg 1
• Target total daily dose: 1.2 mg/kg 1
• Maximum daily dose: 1.4 mg/kg 1
• Dosing can be administered once daily in the morning or divided into two doses (morning and late afternoon) 1

For Children and Adolescents over 70 kg and Adults:

• Initial daily dose: 40 mg 1
• Target total daily dose: 80 mg 1
• Maximum daily dose: 100 mg 1
• Can be administered as a single daily dose or split into two evenly divided doses 2, 3

Administration Recommendations

• Atomoxetine can be administered as a single morning dose or divided into two doses (morning and late afternoon/evening) 1
• Once-daily dosing has been shown to be effective with symptom control extending throughout the day and into the evening 4
• Atomoxetine should be titrated gradually to achieve maximum benefit with minimum adverse effects 5
• Start with lower doses and increase gradually based on clinical response 5

Special Populations and Considerations

Adolescents:

• Atomoxetine is particularly useful for adolescents at risk for substance abuse as it has no abuse potential and is not a controlled substance 5
• For adolescents who drive, atomoxetine provides continuous symptom coverage throughout the day 5

Hepatic Impairment:

• Dosage adjustment is required in patients with hepatic impairment 1

CYP2D6 Considerations:

• Dose adjustment is necessary for patients who are known CYP2D6 poor metabolizers or taking strong CYP2D6 inhibitors 1
• Poor metabolizers have greater exposure to and slower elimination of atomoxetine than extensive metabolizers 6

Monitoring Requirements

During Treatment:

• Monitor for suicidality, especially in children and adolescents (boxed warning) 1
• Monitor blood pressure and heart rate regularly 1, 5
• Track height and weight in pediatric patients 1
• Assess for clinical worsening or unusual changes in behavior 1

Potential Adverse Effects:

• Most common: decreased appetite, headache, stomach pain, nausea, vomiting, somnolence 6
• Cardiovascular: increased blood pressure and heart rate 5
• Initial somnolence and gastrointestinal symptoms, particularly if dosage is increased too rapidly 5

Clinical Efficacy Considerations

• Atomoxetine has a smaller effect size (approximately 0.7) compared to stimulants (effect size approximately 1.0) 5
• Atomoxetine provides "around-the-clock" effects rather than time-limited coverage 5
• Full therapeutic effects may take 6-12 weeks to be observed, unlike the rapid onset of stimulants 5
• Atomoxetine is generally recommended as a second-line therapy after stimulants in many guidelines, though approval status varies by country 5

Advantages of Atomoxetine

• No abuse potential, making it suitable for patients with substance use concerns 5, 7
• May be preferred in patients with comorbid tic disorders, Tourette's disorder, or anxiety 5
• Provides continuous 24-hour symptom control 5
• Can be used as augmentation to stimulant treatment when needed 5

Remember that atomoxetine is typically considered after stimulants have been tried, unless there are specific contraindications to stimulants or patient/family preference for a non-stimulant medication 5.