When to optimize vs switch to a different stimulant for a patient currently taking Vyvanse (lisdexamfetamine) 40 mg daily, according to the Canadian Attention Deficit Hyperactivity Disorder Resource Alliance (CADDRA) guidelines?

When to Optimize vs Switch Stimulants for Vyvanse 40mg Daily

Optimize the current Vyvanse dose first by titrating up to 70mg daily before switching to a different stimulant class, as inadequate response at 40mg does not constitute treatment failure when the maximum approved dose has not been reached. 1

Optimization Strategy: Titrate Current Vyvanse First

The standard approach is to maximize the current stimulant before switching classes. For Vyvanse specifically:

• Increase by 10mg weekly based on clinical response and tolerability, with a maximum approved daily dose of 70mg 1
• The current 40mg dose is in the mid-range of the therapeutic window (30-70mg), leaving substantial room for optimization 1
• Most common maintenance doses are 50-70mg daily in clinical practice, indicating that 40mg is often subtherapeutic 1
• Assess therapeutic response and tolerability before each dose increase to minimize side effects, typically requiring 2-4 weeks to reach optimal dosing 1

Critical Monitoring During Titration

• Obtain ADHD rating scales weekly during dose adjustment to objectively track symptom improvement 1
• Monitor systematically for side effects by asking specific questions about insomnia, anorexia, headaches, and weight loss 1
• Track blood pressure, pulse, height, and weight at each visit 1
• Schedule at least monthly follow-up after stabilization to assess ongoing efficacy and side effects 1

When to Switch to a Different Stimulant Class

Switch to methylphenidate-based stimulants only after:

1. Maximum dose reached (70mg Vyvanse) without adequate symptom control 1
2. Dose-limiting adverse effects that prevent further titration despite suboptimal response 2
3. Persistent inadequate response after 4-6 weeks at maximum tolerated dose 2

Evidence Supporting Class Switching

• Approximately 40% of patients respond to both methylphenidate and amphetamine classes, while 40% respond to only one 3
• If inadequate response occurs after adequate treatment with one stimulant class (amphetamine/Vyvanse), trial the other class (methylphenidate) before considering non-stimulants 1
• Lisdexamfetamine should be the preferred next option over non-stimulants if no desired benefit is observed after adequate treatment with methylphenidate 1

Definition of Inadequate Response

A meaningful definition of inadequate response is failure to produce sufficient reduction of symptoms to achieve functional improvement, not merely a percentage change on rating scales 2. Specifically assess:

• Functional impairment across at least two different settings (work/school, home, social) 4
• Core ADHD symptoms (inattention, hyperactivity, impulsivity) using standardized rating scales 1
• Quality of life and executive function improvements 1

Common Pitfalls to Avoid

• Starting at too high a dose can lead to unnecessary side effects and decreased medication adherence 1
• Assuming 40mg is adequate without systematic titration—70% of patients respond optimally when proper titration protocols are followed 3
• Switching prematurely before reaching maximum approved dose of 70mg daily 1
• Failure to systematically assess both benefits and side effects during titration using objective measures 1
• If the top recommended dose (70mg) does not help, more is not necessarily better—consider switching to methylphenidate class or adding adjunctive therapy instead 3

Alternative Approach: Adjunctive Therapy for Partial Responders

For patients who are partial responders to Vyvanse despite adequate adherence and dose optimization, consider adding:

• Guanfacine extended-release (1-4mg daily) as FDA-approved adjunctive therapy, particularly useful for residual symptoms, sleep disturbances, or comorbid oppositional symptoms 2, 1
• Atomoxetine as adjunctive therapy, though this combination requires careful monitoring 2
• Clonidine extended-release as an alternative alpha-2 agonist option 2