What is the recommended dosage and treatment guidelines for Strattera (atomoxetine) in patients with Attention Deficit Hyperactivity Disorder (ADHD)?

Dosage and Treatment Guidelines for Strattera (Atomoxetine) in ADHD

For patients with ADHD, Strattera (atomoxetine) should be dosed at 0.5 mg/kg/day initially, then titrated to a target dose of 1.2 mg/kg/day, with a maximum of 1.4 mg/kg/day in children and adolescents up to 70 kg, or 40 mg initially with a target of 80 mg and maximum of 100 mg daily for those over 70 kg and adults. 1

Dosing Recommendations by Age Group

Children and Adolescents (up to 70 kg)

• Initial dose: 0.5 mg/kg/day 1
• Target dose: 1.2 mg/kg/day 1
• Maximum dose: 1.4 mg/kg/day 1
• Administration: Can be given as a single morning dose or divided into two doses (morning and late afternoon) 1

Adolescents (over 70 kg) and Adults

• Initial dose: 40 mg/day 1
• Target dose: 80 mg/day 1
• Maximum dose: 100 mg/day 1
• Administration: Can be given as a single daily dose or divided into two doses 1

Special Dosing Considerations

Hepatic Impairment

• Dosage adjustment required for patients with hepatic impairment 1
• For moderate hepatic impairment (Child-Pugh Class B): Reduce to 50% of normal dose
• For severe hepatic impairment (Child-Pugh Class C): Reduce to 25% of normal dose

CYP2D6 Poor Metabolizers

• Dosage adjustment required for known CYP2D6 poor metabolizers or patients taking strong CYP2D6 inhibitors 1
• These patients have greater exposure to and slower elimination of atomoxetine

Treatment Guidelines by Age Group

Preschool-Aged Children (4-5 years)

• Behavioral therapy is first-line treatment 2
• Atomoxetine is not FDA-approved for this age group, though limited evidence suggests it may be well-tolerated 3

Elementary School-Aged Children (6-11 years)

• FDA-approved medications including atomoxetine are recommended, preferably combined with behavioral therapy 2
• Atomoxetine is considered after stimulants in order of evidence strength (stimulants > atomoxetine > extended-release guanfacine > extended-release clonidine) 2

Adolescents (12-18 years)

• FDA-approved medications including atomoxetine are recommended with the adolescent's assent 2
• Behavioral therapy is also recommended, preferably in combination with medication 2

Titration and Monitoring

• Start with lower doses and titrate gradually to minimize side effects 1
• For optimal tolerability, consider divided dosing during initial titration 4
• Titrate doses to achieve maximum benefit with minimum adverse effects 2
• Allow at least 6-8 weeks to evaluate the full efficacy of atomoxetine 4
• Monitor vital signs (blood pressure and heart rate) regularly due to potential cardiovascular effects 1
• Monitor height and weight in pediatric patients 1
• Screen for suicidal ideation, particularly in children and adolescents 1

Clinical Considerations for Atomoxetine Selection

Advantages of Atomoxetine

• Non-stimulant medication with no abuse potential 5, 6
• Not a controlled substance, allowing easier prescription management 5, 6
• Once-daily dosing option with effects that can extend through the day and evening 4
• May be beneficial for patients with comorbid anxiety, tics, or sleep disturbances 4
• Can be discontinued abruptly without rebound effects 4

Potential Side Effects to Monitor

• Common side effects: headache, abdominal pain, decreased appetite, vomiting, somnolence, nausea 5
• Cardiovascular effects: small increases in heart rate and blood pressure 1, 5
• Black box warning: increased risk of suicidal ideation in children and adolescents 1
• Rare but serious: liver injury (monitor for jaundice or laboratory evidence of liver injury) 1

Contraindications

• Hypersensitivity to atomoxetine or other constituents 1
• Use within 2 weeks of MAOI discontinuation 1
• Narrow-angle glaucoma 1
• Pheochromocytoma or history of pheochromocytoma 1
• Severe cardiovascular disorders that might deteriorate with clinically important increases in heart rate and blood pressure 1

Switching from Stimulants to Atomoxetine

• Can initiate atomoxetine while cross-tapering with methylphenidate 4
• Approximately 50% of non-responders to methylphenidate will respond to atomoxetine 4
• Approximately 75% of responders to methylphenidate will also respond to atomoxetine 4

Atomoxetine has demonstrated efficacy in improving ADHD symptoms and social/family functioning, with clinical trials showing significant improvements compared to placebo 7. While it is generally considered after stimulants in treatment algorithms due to comparative efficacy, it remains an important option, particularly for patients with specific comorbidities or concerns about stimulant use.