Combining Stimulants for ADHD Treatment

Introduction to Combination Therapy

• The American Academy of Child and Adolescent Psychiatry recommends a maximum total daily amphetamine dose of 40mg, though clinical practice sometimes extends to 50mg 4

Critical Dosing Considerations

• Adding Dexedrine 5mg BID to Vyvanse 50mg provides an additional 10mg of immediate-release dextroamphetamine daily, yielding a total daily amphetamine equivalent of approximately 60-65mg 1, 2, 3
• Both Dexedrine 5mg doses must be completed before 2:00-3:00 PM to prevent insomnia 1, 2, 3, 4

Mandatory Monitoring Parameters

• Blood pressure and heart rate should be monitored at every visit (quarterly minimum in adults) to detect hypertension or tachycardia 4, 5
• Weight should be monitored at each visit to assess for appetite suppression and nutritional adequacy 4, 5
• Sleep quality and duration should be monitored, as late-day dosing commonly causes insomnia 1, 2, 3
• Mood changes, irritability, and anxiety should be monitored, which increase at higher amphetamine doses 4

Important Safety Caveats

• Higher amphetamine doses increase the risk for hypertension and tachycardia 5
• If maximum recommended doses fail to control symptoms adequately, increasing the dose further rarely provides additional benefit 5
• Approximately 90% of patients respond when both amphetamine and methylphenidate classes are tried 6

Alternative Approach to Consider

• The American Academy of Child and Adolescent Psychiatry suggests starting with dextroamphetamine 10-12.5mg total daily for patients on lisdexamfetamine 50mg requiring additional coverage 6

Common Pitfalls to Avoid

• Do not give the afternoon Dexedrine dose after 2:00-3:00 PM, as this is the most common cause of treatment-related insomnia 1, 2, 3, 4
• Do not continue escalating doses indefinitely if symptom control remains inadequate—this signals the need for a different therapeutic approach 4, 5