What is the recommended dosage of Foquest (lisdexamfetamine) for a patient switching from Vyvanse (lisdexamfetamine) 60mg?

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Switching from Vyvanse to Foquest: Dosage Recommendation

I cannot provide a specific dosage recommendation for switching from Vyvanse 60mg to Foquest because the provided evidence contains no information about Foquest whatsoever.

Critical Issue with This Question

The evidence base provided exclusively discusses lisdexamfetamine (Vyvanse), not Foquest. 1, 2, 3

What the Evidence Actually Addresses

The available evidence covers:

  • Lisdexamfetamine formulations and dosing: Vyvanse is available in capsules from 10-70mg, with typical starting doses of 30mg and weekly titration in 10-20mg increments 2

  • Switching between different stimulant classes: One guideline discusses switching from Vyvanse (an amphetamine prodrug) to Focalin XR (a methylphenidate), which can be done without tapering or washout periods 4

  • Lisdexamfetamine pharmacology: It is a prodrug requiring enzymatic hydrolysis to convert to active d-amphetamine 3, 5

Why This Matters Clinically

Without manufacturer guidance, prescribing information, or clinical trial data on Foquest specifically, I cannot recommend an equivalent dose. Different formulations of the same active ingredient may have:

  • Different pharmacokinetic profiles
  • Different bioavailability
  • Different duration of action
  • Different dosing equivalencies

What You Should Do

Consult the Foquest product monograph or prescribing information directly to determine:

  • Whether direct conversion ratios are provided by the manufacturer
  • The recommended starting dose when switching from other stimulants
  • Any specific titration protocols for patients transitioning from lisdexamfetamine

If Foquest is also lisdexamfetamine (which the question implies but the evidence doesn't confirm), the manufacturer's guidance on bioequivalence would be essential before assuming a 1:1 dose conversion.

References

Guideline

Lisdexamfetamine Formulation and Administration

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Switching from Vyvanse to Focalin XR: A Guideline Summary

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Lisdexamfetamine.

Paediatric drugs, 2007

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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