How to switch from 25mg of Adderall (amphetamine and dextroamphetamine) to Strattera (atomoxetine)?

Switching from 25mg Adderall to Strattera (Atomoxetine)

When switching from 25mg Adderall to Strattera, you should initiate atomoxetine at 40mg daily (or 0.5 mg/kg if patient weighs <70kg) while discontinuing Adderall abruptly without tapering, then titrate atomoxetine to a target dose of 80mg daily (or 1.2 mg/kg) after a minimum of 3 days. 1

Discontinuation of Adderall

• Adderall can be discontinued abruptly without tapering when switching to another ADHD medication 2
• Amphetamines like Adderall should be discontinued or decreased when problematic, and behavioral therapies can be considered as adjunctive treatment 2
• There is no washout period required between stopping Adderall and starting atomoxetine, as these medications work through different mechanisms (dopamine/norepinephrine release vs. selective norepinephrine reuptake inhibition) 2, 3

Initiation of Atomoxetine (Strattera)

For Patients Weighing ≤70 kg:

• Start atomoxetine at 0.5 mg/kg/day (approximately 40mg for most adults) 1
• After a minimum of 3 days, increase to the target dose of 1.2 mg/kg/day 1
• Maximum dose should not exceed 1.4 mg/kg or 100mg daily, whichever is less 1

For Patients Weighing >70 kg and Adults:

• Start atomoxetine at 40mg daily 1
• After a minimum of 3 days, increase to target dose of 80mg daily 1
• After 2-4 additional weeks, may increase to maximum of 100mg if optimal response not achieved 1

Dosing Schedule Options

• Atomoxetine can be administered either as a single daily dose in the morning OR as evenly divided doses in morning and late afternoon/early evening 1
• Single morning dosing has been shown effective into the evening hours 3
• Atomoxetine may be taken with or without food 1

Timeline for Therapeutic Effect

• Expect 6-12 weeks until full therapeutic effects are observed with atomoxetine, which is significantly longer than stimulants 2
• This delayed onset is a critical counseling point, as patients switching from the immediate effects of Adderall may become discouraged 2
• Some improvement may be seen earlier, but optimal response typically requires several weeks 1, 3

Monitoring During the Switch

• Check blood pressure and pulse at baseline and regularly during treatment, as atomoxetine can cause increases in both parameters 2, 1
• Monitor for emergence of suicidal ideation, particularly in the first few weeks, as atomoxetine carries a black-box warning for this risk 3
• Assess efficacy using standardized ADHD rating scales when possible 4
• Monitor for common adverse effects including decreased appetite, headache, abdominal pain, nausea, and somnolence 3

Special Dosing Considerations

If Patient is Taking CYP2D6 Inhibitors:

• If the patient is on strong CYP2D6 inhibitors (paroxetine, fluoxetine, quinidine) or is a known CYP2D6 poor metabolizer, maintain the initial dose of 40mg (or 0.5 mg/kg) for 4 weeks before increasing to 80mg (or 1.2 mg/kg), and only increase if symptoms fail to improve and initial dose is well tolerated 1

Hepatic Impairment:

• For moderate hepatic impairment (Child-Pugh Class B): reduce initial and target doses to 50% of normal 1
• For severe hepatic impairment (Child-Pugh Class C): reduce initial and target doses to 25% of normal 1

Key Advantages of This Switch

• Atomoxetine provides "around-the-clock" symptom control without the need for multiple daily dosing 2
• It is an uncontrolled substance with negligible abuse potential, making it particularly useful for patients with comorbid substance use disorders 2, 3, 5
• Atomoxetine may be preferable for patients with comorbid anxiety, tics, or Tourette's disorder 2

Important Caveats

• Atomoxetine has a smaller effect size compared to stimulants, including being significantly less effective than extended-release methylphenidate formulations and extended-release mixed amphetamine salts 2, 3, 5
• Patients should be counseled about the delayed therapeutic onset to maintain adherence during the transition period 2
• Screen for personal or family history of bipolar disorder, mania, or hypomania before initiating atomoxetine 1
• Atomoxetine capsules should be swallowed whole and not opened 1