Is it safe to combine Mydayis (amphetamine) with Adderall (amphetamine and dextroamphetamine) for the treatment of attention-deficit/hyperactivity disorder (ADHD)?

Combining Mydayis with Adderall is Not Recommended Due to Safety Concerns

Combining Mydayis (mixed amphetamine salts extended-release) with Adderall (mixed amphetamine salts) is not recommended as both contain the same active ingredients (amphetamine salts) and would significantly increase the risk of adverse cardiovascular effects without providing additional therapeutic benefit. 1

Pharmacological Considerations

• Both medications contain amphetamine salts:

  • Mydayis: Mixed amphetamine salts extended-release (longer duration)
  • Adderall: Mixed amphetamine salts (shorter duration)

• Combining these medications would essentially:

  • Double the amphetamine dose
  • Create unpredictable pharmacokinetics
  • Increase risk of side effects

Safety Concerns

Cardiovascular Risks

• Stimulant medications are known to cause:

  • Increases in blood pressure
  • Increases in heart rate
  • Potential QTc interval changes 2

• Even at therapeutic doses, stimulants cause small but statistically significant increases in blood pressure and heart rate 1, 2

• While rare, serious cardiovascular events have been reported with stimulant use, including:

  • Acute myocardial infarction 3
  • Arrhythmias
  • Hypertension requiring medication discontinuation 4

Other Safety Concerns

• Doubling amphetamine exposure would increase risk of:
  • Insomnia
  • Decreased appetite
  • Weight loss
  • Irritability
  • Anxiety
  • Potential for substance abuse/dependence

Evidence Against Combination Therapy

The American Academy of Child and Adolescent Psychiatry specifically notes that "combining Adderall XR and Vyvanse may increase the risk of adverse effects, without clear therapeutic benefit" 1. This same principle applies to combining Mydayis with Adderall, as they contain the same active ingredients.

In clinical studies of amphetamine formulations:

• Therapeutic doses of MAS XR (mixed amphetamine salts extended-release) up to 60 mg/day were found to be effective and generally safe 5, 4
• However, these studies did not evaluate combining multiple amphetamine products

Alternative Approaches

If current ADHD medication is not providing adequate symptom control:

1. Optimize single-agent therapy first:

   • Adjust the dose of the current medication (if not at maximum)
   • Consider changing the timing of administration

2. Switch to a different formulation:

   • If using Adderall, consider switching completely to Mydayis for longer duration
   • If using Mydayis, consider switching completely to Adderall if shorter duration is needed

3. Consider alternative stimulant class:

   • Switch to methylphenidate-based products if amphetamine formulations are not effective

4. Consider non-stimulant options:

   • Atomoxetine
   • Alpha-2 agonists (guanfacine-XR, clonidine-XR)

Monitoring Recommendations

For patients on any stimulant medication:

• Regular monitoring of blood pressure and heart rate
• Assessment of sleep quality, appetite, and weight
• Evaluation of mood and potential side effects
• Cardiovascular assessment for patients with risk factors

Key Pitfall to Avoid

The most dangerous pitfall would be assuming that because both medications are FDA-approved individually, combining them would be safe. This is not the case with stimulant medications containing the same active ingredients, as it effectively creates an unpredictable and potentially dangerous overdose situation.