What Vyvanse (lisdexamfetamine) dose is equivalent to Adderall XR 30 mg in a bipolar patient who is stable on a mood stabilizer?

Converting Adderall XR 30 mg to Vyvanse in a Bipolar Patient

Start with Vyvanse 50 mg once daily in the morning as the equivalent dose to Adderall XR 30 mg, ensuring mood stabilizers are optimized before initiating any stimulant therapy. 1, 2

Critical Safety Requirement for Bipolar Patients

Mood stabilizers must be established and optimized before introducing stimulant medications in patients with ADHD and comorbid bipolar disorder. This is the standard of care to minimize the risk of manic episodes and ensure effective treatment of both conditions. 1

• Never initiate stimulant therapy in patients with unstable bipolar disorder or active manic/hypomanic symptoms, as stimulants can precipitate or worsen mood episodes 1
• The standard of care remains mood stabilizer plus stimulant, not stimulant monotherapy, for patients with confirmed bipolar disorder 1
• A randomized controlled trial demonstrated that low-dose mixed amphetamine salts were safe and effective for comorbid ADHD only after mood symptoms were stabilized with divalproex 1

Pharmacokinetic Basis for Conversion

Lisdexamfetamine (Vyvanse) is a prodrug that is enzymatically converted to dextroamphetamine after oral ingestion, with the l-lysine amino acid cleaved off through rate-limited hydrolysis in the blood. 2, 3 This prodrug mechanism provides:

• Extended duration of action up to 14 hours post-dose in adults 4
• Lower abuse potential compared to immediate-release amphetamines due to the rate-limited conversion process 3, 5
• More stable plasma concentrations without rapid peaks 3

Specific Dosing Recommendation

Begin with Vyvanse 50 mg once daily in the morning when converting from Adderall XR 30 mg. 2 The conversion rationale:

• Adderall XR 30 mg contains approximately 15 mg of dextroamphetamine-equivalent active drug 2
• Vyvanse 70 mg converts to approximately 20-23 mg of dextroamphetamine after prodrug conversion 2, 3
• Therefore, Vyvanse 50 mg (converting to ~14-16 mg dextroamphetamine) provides the closest equivalent to Adderall XR 30 mg 2

Alternative starting approach: If you prefer a more conservative conversion, start with Vyvanse 40 mg and titrate upward by 10-20 mg weekly based on ADHD symptom response, with a maximum dose of 70 mg daily. 1, 2

Titration Protocol

• Increase by 10-20 mg increments weekly based on ADHD symptom control and tolerability 1, 2
• Maximum recommended dose is 70 mg daily for adults 2, 4
• Administer in the morning to minimize sleep disturbances 6
• Allow 6-8 weeks at the optimized dose to fully assess efficacy 1

Monitoring Requirements During Conversion

Cardiovascular monitoring: Measure blood pressure and pulse at baseline and each visit during titration. 1, 2

Mood stability: Monitor closely for any signs of mood destabilization, including:

• Emergence of manic or hypomanic symptoms 1
• Increased irritability or agitation 1
• Sleep disturbances beyond typical stimulant effects 1

ADHD symptom tracking: Use standardized ADHD rating scales weekly during the first 4 weeks to assess symptom response. 1

Common side effects: Monitor for decreased appetite, insomnia, headache, and breakthrough symptoms in late afternoon/evening. 2, 5

Critical Pitfalls to Avoid

• Do not assume a 1:1 mg conversion between Adderall XR and Vyvanse; the prodrug mechanism requires adjustment of the conversion ratio 2
• Do not initiate or increase stimulant doses if mood symptoms are unstable, as this can precipitate psychiatric decompensation 1
• Do not discontinue mood stabilizers when starting stimulant therapy; both medications must be maintained concurrently 1
• Monitor for breakthrough symptoms in the late afternoon/evening during the first 2 weeks, as Vyvanse's duration of action may differ from Adderall XR in individual patients 2

Expected Outcomes

• Approximately 70-80% of patients achieve good ADHD symptom control when amphetamine-based stimulants are properly titrated 1
• Vyvanse provides efficacy for a full treatment day, extending up to 14 hours post-dose in adults 4
• The prodrug formulation of Vyvanse offers more consistent symptom coverage with lower abuse potential compared to immediate-release formulations 3, 5