What is the recommended starting dose for Strattera (atomoxetine) in patients, including children and adolescents, with attention deficit hyperactivity disorder (ADHD)?

Starting Dose for Strattera (Atomoxetine)

For children and adolescents weighing ≤70 kg, start atomoxetine at 0.5 mg/kg/day and increase after a minimum of 3 days to a target dose of 1.2 mg/kg/day; for those weighing >70 kg and adults, start at 40 mg/day and increase after a minimum of 3 days to a target of 80 mg/day. 1

Pediatric Dosing (Children and Adolescents ≤70 kg)

• Initial dose: 0.5 mg/kg/day (total daily dose), administered either as a single morning dose or divided into morning and late afternoon/early evening doses 1
• Target dose: 1.2 mg/kg/day, reached after a minimum of 3 days from initiation 1
• Maximum dose: 1.4 mg/kg/day or 100 mg/day, whichever is less 1
• No additional benefit has been demonstrated for doses higher than 1.2 mg/kg/day 1

Dosing for Larger Pediatric Patients (>70 kg) and Adults

• Initial dose: 40 mg/day, administered as a single morning dose or divided into morning and late afternoon/early evening doses 1
• Target dose: 80 mg/day, reached after a minimum of 3 days from initiation 1
• After 2-4 additional weeks at 80 mg/day, may increase to maximum of 100 mg/day in patients who have not achieved optimal response 1
• The American College of Obstetricians and Gynecologists recommends titrating every 7-14 days (40 mg → 60 mg → 80 mg daily) 2, 3

Titration Schedule and Monitoring

• Allow 6-12 weeks for full therapeutic effects to be observed, as atomoxetine has a slower onset compared to stimulants 2
• Maintain weekly contact during initial titration and systematically assess for specific side effects at each adjustment 2
• After dose stabilization, schedule follow-up appointments at least monthly 2
• Atomoxetine can be administered with or without food 1

Special Populations Requiring Dose Adjustment

Hepatic Impairment

• Moderate hepatic impairment (Child-Pugh Class B): Reduce initial and target doses to 50% of normal dose 1
• Severe hepatic impairment (Child-Pugh Class C): Reduce initial and target doses to 25% of normal dose 1

CYP2D6 Poor Metabolizers or Concurrent Strong CYP2D6 Inhibitors

• For patients ≤70 kg: Start at 0.5 mg/kg/day and only increase to usual target of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and initial dose is well tolerated 1
• For patients >70 kg and adults: Start at 40 mg/day and only increase to usual target of 80 mg/day if symptoms fail to improve after 4 weeks and initial dose is well tolerated 1
• Strong CYP2D6 inhibitors include paroxetine, fluoxetine, and quinidine 1

Clinical Context and Important Considerations

• Atomoxetine is generally used as second-line therapy after stimulants, though it may be first-line in patients with comorbid substance use disorders, tic/Tourette's disorder, or those who prefer a non-controlled substance 2
• For preschool-aged children (4-5 years), start with lower doses and increase in smaller increments due to slower metabolism rates 2
• Screen for bipolar disorder, mania, or hypomania (personal or family history) prior to initiating treatment 1
• Atomoxetine can be discontinued without tapering 1
• Capsules should be taken whole and not opened 1

Common Pitfalls to Avoid

• Do not exceed maximum doses: 1.4 mg/kg/day or 100 mg/day (whichever is less) in children/adolescents, or 100 mg/day in adults 1
• Do not rush titration—allow minimum of 3 days between initial dose and target dose 1
• Monitor closely for suicidality, clinical worsening, and unusual behavioral changes, particularly in the initial treatment period 4
• In adolescents, assess for substance abuse symptoms before initiating treatment and monitor prescription-refill requests for signs of misuse or diversion 2