Combining Adderall with Vyvanse 50mg is Not Recommended
Adding Adderall to a patient already taking Vyvanse 50mg is not a standard practice and should generally be avoided, as both medications are amphetamine-based stimulants that would result in excessive total amphetamine exposure and increased risk of cardiovascular and psychiatric adverse effects. 1, 2
Why Combination Therapy is Problematic
Vyvanse (lisdexamfetamine) is a prodrug that converts to dextroamphetamine in the body, providing therapeutic effects through the same mechanism as Adderall (which contains mixed amphetamine salts including dextroamphetamine). 3, 4
Combining these medications would essentially be "stacking" amphetamines, leading to cumulative cardiovascular effects (elevated blood pressure, tachycardia) and increased risk of insomnia, appetite suppression, anxiety, and potential for abuse. 1, 5
Maximum recommended daily amphetamine doses should not be exceeded: guidelines specify 40-50mg total daily dose for amphetamines in adults, and your patient is already at 50mg lisdexamfetamine equivalent. 1, 2, 6
The Correct Approach: Optimize or Switch
If Current Vyvanse 50mg is Inadequate:
First, confirm the patient is actually taking the medication consistently and assess for factors reducing efficacy (poor sleep, untreated comorbid conditions like anxiety or depression, substance use). 2
Vyvanse 50mg is not the maximum dose - the medication can be increased:
- Titrate Vyvanse upward in 10-20mg increments weekly if tolerated
- Maximum approved dose is 70mg daily for adults with ADHD 5
- Reassess symptom control using standardized ADHD rating scales after each increase 2, 6
If Vyvanse Causes Intolerable Side Effects or Reaches Maximum Without Benefit:
Switch to a different stimulant formulation rather than adding a second stimulant: 1, 2
- Consider switching to Adderall XR starting at 10mg daily, titrating by 5mg weekly up to 50mg maximum 2, 6, 7
- Alternatively, consider methylphenidate-based stimulants (Concerta, Ritalin LA) which work through different mechanisms on dopamine reuptake 1
If stimulants are ineffective or poorly tolerated overall, add or switch to non-stimulant options: 1, 2
- Atomoxetine, guanfacine, or bupropion can be considered as alternatives or adjuncts
- These have different mechanisms and can be safely combined with stimulants if truly needed 1
Critical Monitoring if Any Dose Changes Occur:
- Check blood pressure and pulse at baseline and with each dose adjustment - adults on stimulants require quarterly vital sign monitoring at minimum 1, 2, 6
- Assess for cardiovascular symptoms (chest pain, palpitations, syncope) which would contraindicate further stimulant use 1
- Monitor weight regularly as appetite suppression is dose-dependent 1, 6, 7
- Systematically assess both therapeutic response and side effects (insomnia, anxiety, irritability, tics) before any dose increase 1, 2
Common Pitfall to Avoid:
The most dangerous error would be prescribing immediate-release Adderall for "breakthrough" symptoms in addition to Vyvanse - this practice, while occasionally seen, violates maximum dosing guidelines and dramatically increases cardiovascular risk and abuse potential. 1, 5