When to switch from Vyvanse (lisdexamfetamine) to Adderall (amphetamine and dextroamphetamine)?

When to Switch from Vyvanse to Adderall

Switching from Vyvanse (lisdexamfetamine) to Adderall (amphetamine and dextroamphetamine) should be considered when patients experience inadequate symptom control throughout the day, unacceptable side effects, or cost concerns with Vyvanse.

Key Considerations for Switching

Indications for Switching to Adderall

• Inadequate duration of effect: If Vyvanse's 13-14 hour duration 1 is not matching the patient's needs
• Suboptimal response: Approximately 25% of patients who respond to one stimulant may not respond to another 2
• Side effect profile: Different tolerability issues between the medications
• Cost concerns: Vyvanse typically costs more than generic Adderall formulations

Clinical Differences Between Medications

1. Pharmacological Properties:

   • Vyvanse is a prodrug that is hydrolyzed to d-amphetamine in the blood 3
   • Adderall contains a mixture of amphetamine and dextroamphetamine salts that are immediately active
   • Both ultimately work by increasing dopamine and norepinephrine in the synaptic cleft 3

2. Onset and Duration:

   • Vyvanse provides more consistent plasma concentrations throughout the day 1
   • Adderall immediate-release has faster onset but shorter duration
   • Adderall XR provides intermediate duration compared to Vyvanse

Switching Protocol

Recommended Approach

1. Gradual cross-tapering is preferred to minimize withdrawal effects and maintain symptom control 4:

   • Begin Adderall at a low dose (5-10 mg daily) 5
   • Gradually reduce Vyvanse while increasing Adderall over 1-2 weeks
   • Monitor closely for adverse effects during transition

2. Dosage Equivalence (approximate):

   • 30 mg Vyvanse ≈ 10 mg Adderall
   • 50 mg Vyvanse ≈ 20 mg Adderall
   • 70 mg Vyvanse ≈ 30 mg Adderall

Monitoring During Transition

• Cardiovascular parameters: Heart rate and blood pressure should be checked regularly 5
• Side effects: Monitor for common stimulant side effects (decreased appetite, insomnia, irritability) 1
• Efficacy: Assess ADHD symptom control throughout the day

Important Cautions

• Avoid abrupt discontinuation of Vyvanse to prevent withdrawal symptoms 4
• Contraindications apply to both medications: advanced cardiovascular disease, hypertension, hyperthyroidism, glaucoma, agitation, history of substance abuse, psychosis or mania 5
• Special populations: Elderly patients and those with pre-existing medical conditions require more careful monitoring 5

Clinical Pearls

• Allow at least 2-3 weeks on the new medication regimen before making final efficacy assessments
• Consider time of day when symptoms are most problematic when choosing between immediate-release and extended-release formulations
• Some patients may benefit from a combination approach (e.g., Adderall XR in morning with immediate-release later in day) for optimal symptom control

Remember that both medications are controlled substances requiring careful prescribing practices and monitoring for potential misuse.