What are the next steps for a patient who switched from Vyvanse (Lisdexamfetamine) 40mg to Adderall (Dextroamphetamine and Amphetamine) 20mg due to insurance issues?

Optimizing ADHD Treatment After Insurance-Mandated Switch

Immediate Assessment and Dose Optimization

Your patient's current Adderall 20mg daily dose is likely subtherapeutic compared to the previous Vyvanse 40mg, and requires upward titration to achieve equivalent symptom control. 1

Understanding the Conversion Gap

• Vyvanse 40mg and Adderall 20mg are not equivalent doses - there is no established direct dose equivalency between lisdexamfetamine and mixed amphetamine salts 2
• Lisdexamfetamine is a prodrug that requires enzymatic hydrolysis to release active d-amphetamine gradually, while Adderall contains both d- and l-amphetamine enantiomers in a 3:1 ratio that are immediately bioavailable 3, 4
• The pharmacokinetic profiles differ significantly: lisdexamfetamine has a 0.6-1.1 hour longer lag time to peak concentrations compared to immediate amphetamine formulations 5

Recommended Titration Protocol

Start by increasing Adderall to 30mg daily (15mg twice daily or 30mg XR once daily), then titrate by 5-10mg weekly increments until optimal symptom control is achieved. 1

• The American Academy of Child and Adolescent Psychiatry recommends dextroamphetamine/amphetamine dosing of 5mg three times daily to 20mg twice daily for adults, with maximum daily doses reaching 40-50mg 1
• Most adults require 20-40mg total daily dose for optimal ADHD symptom control, with some patients requiring up to 65mg daily when lower doses prove insufficient 1
• Your patient's current 20mg daily dose is at the very low end of the therapeutic range and unlikely to provide equivalent coverage to their previous Vyvanse regimen 1

Monitoring During Dose Adjustment

Critical Parameters to Track Weekly

• ADHD symptom control using standardized rating scales (ADHD-RS-IV) to objectively measure improvement 1
• Blood pressure and pulse at each visit, as cardiovascular effects require regular monitoring 1
• Sleep quality and timing - assess for insomnia or difficulty falling asleep, which may require dose timing adjustments 1
• Appetite and weight changes - track at each visit as appetite suppression is common with stimulants 1

Expected Timeline for Optimization

• Stimulants work within hours to days, allowing rapid assessment of efficacy at each dose level 1
• Plan for 4-6 weeks of systematic titration to reach optimal dosing, with weekly 5-10mg increases 1
• 70-80% of patients respond optimally to stimulants when proper titration protocols are followed 1

Common Pitfalls to Avoid

Do not assume the current 20mg dose is adequate simply because it represents a "switch" from Vyvanse - systematic titration to optimal effect is more important than arbitrary dose conversions 1

• Avoid stopping titration prematurely before reaching therapeutic doses of 30-40mg daily in most adults 1
• Do not add additional medications for persistent ADHD symptoms before optimizing the stimulant dose first 1
• Never combine with MAO inhibitors due to risk of hypertensive crisis - ensure at least 14 days have elapsed if switching from an MAOI 1

Alternative Considerations if Adderall Proves Inadequate

If inadequate response occurs after reaching 40-50mg daily of Adderall:

• Trial methylphenidate-based stimulants (Concerta, Ritalin LA) as approximately 40% of patients respond to only one stimulant class 1
• Consider switching back to lisdexamfetamine if insurance coverage changes, as it may provide superior all-day coverage with once-daily dosing 1
• Non-stimulant options (atomoxetine, guanfacine) should only be considered after adequate trials of both amphetamine and methylphenidate classes 1