Converting Concerta 27mg to Vyvanse
Start Vyvanse at 30mg once daily in the morning when switching from Concerta 27mg, as there is no established direct dose equivalency between methylphenidate and lisdexamfetamine, requiring empiric dosing with subsequent titration based on clinical response. 1, 2
Conversion Approach
Discontinue Concerta 27mg abruptly without tapering when switching to Vyvanse, as no washout period is required between stimulant medications. 3
The recommended starting dose of lisdexamfetamine is 20-30mg once daily in the morning, with 30mg being appropriate for patients already on moderate-dose methylphenidate like Concerta 27mg. 2
Methylphenidate and amphetamine-based medications are fundamentally different drug classes with distinct mechanisms of action and pharmacokinetics, making mathematical dose conversions unreliable and clinically inappropriate. 1, 3
Titration Strategy
Increase Vyvanse by 10mg weekly increments based on clinical response, up to a maximum of 70mg daily. 2
Expect immediate therapeutic effects within hours of the first Vyvanse dose, similar to other stimulant medications—full clinical benefit does not require weeks of treatment. 1
Individual response varies significantly between methylphenidate and amphetamine classes, so avoid assuming equivalent efficacy at any particular dose ratio. 1
Monitoring Requirements
Monitor blood pressure and heart rate at each visit, as cardiac effects can occur with both methylphenidate and amphetamine medications. 1
Assess ADHD symptom control throughout the day, as lisdexamfetamine demonstrates efficacy up to 14 hours post-dose in adults, providing extended coverage compared to some methylphenidate formulations. 4
Common Pitfalls to Avoid
Never attempt mathematical dose conversions based on stimulant equivalency tables, as these are unreliable for cross-class switches between methylphenidate and amphetamines. 1
Avoid taking Vyvanse inconsistently with regard to food intake, as high-fat meals can significantly affect amphetamine absorption and early drug exposure. 3
Do not assume that a patient who responded well to Concerta will have identical response to Vyvanse—individual variability in cross-class stimulant response is substantial and requires careful clinical monitoring. 1