What is the equivalent dose of Vyvanse (lisdexamfetamine) to Adderall (amphetamine and dextroamphetamine) 10mg Extended Release (XR)?

Vyvanse Equivalent to Adderall 10mg XR

For a patient taking Adderall XR 10mg, the equivalent Vyvanse dose is approximately 25mg, based on a conversion ratio of approximately 2.5:1 (Vyvanse:Adderall).

Conversion Calculation

• Applying the established conversion factor of 2.5:1 (Vyvanse:Adderall) to a 10mg Adderall XR dose yields 25mg of Vyvanse 1
• This conversion ratio is derived from guideline recommendations that specify 50mg Vyvanse as equivalent to 20mg Adderall, which mathematically translates to 25mg Vyvanse for 10mg Adderall 1

Practical Implementation

• Start with Vyvanse 30mg once daily in the morning, as this is the lowest available commercial dose and represents a conservative approach that slightly exceeds the calculated 25mg equivalent 1, 2
• The 30mg starting dose accounts for the prodrug metabolism of lisdexamfetamine and provides a safety margin, as Vyvanse must be converted to active d-amphetamine in the body 3, 4
• Morning administration is critical to minimize sleep disturbances 2

Titration Strategy

• Allow at least one week to evaluate response before making dose adjustments 2
• If symptom control is inadequate after one week on Vyvanse 30mg, increase by 10mg weekly increments up to a maximum of 70mg daily 1, 2
• The usual starting dose range for Vyvanse is 20-30mg once daily 1

Monitoring Requirements

• Assess blood pressure and pulse at the first follow-up visit after conversion 2
• Evaluate target ADHD symptoms using standardized rating scales 2
• Monitor weight at each visit to detect appetite suppression 2

Important Caveats

• Lisdexamfetamine has a delayed onset compared to immediate d-amphetamine, with peak levels occurring approximately 1 hour later, though total drug exposure remains equivalent at equimolar doses 5
• The prodrug formulation provides rate-limited conversion to active d-amphetamine, resulting in a more gradual release profile 4
• Despite the delayed pharmacokinetics, peak subjective effects and cardiovascular responses are similar between lisdexamfetamine and d-amphetamine at equivalent doses 5