What is the best dose of Adderall (amphetamine and dextroamphetamine) XR in the morning and Adderall (amphetamine and dextroamphetamine) IR at lunch for a patient currently taking 25mg of Adderall (amphetamine and dextroamphetamine) twice a day?

Recommended Dosing Strategy for Converting from Adderall IR 25mg Twice Daily to XR + IR Combination

For a patient currently taking 25mg IR twice daily (total 50mg/day), convert to Adderall XR 30mg in the morning plus Adderall IR 10mg at lunch, maintaining the total daily dose of 40mg within FDA-approved maximum limits. 1, 2, 3

Rationale for Dose Reduction

Your patient is currently taking 50mg total daily dose, which exceeds the FDA-approved maximum of 40mg per day 3. The American Academy of Child and Adolescent Psychiatry explicitly states that the maximum total daily dose for amphetamines is 40mg, and clinical practice consensus limits the upper range to 40mg 1, 2. Guidelines emphasize that "if the top recommended dose does not help, more is not necessarily better" 1, 2.

Specific Conversion Recommendation

Morning dose: Adderall XR 30mg upon awakening 1, 3

Lunch dose: Adderall IR 10mg, given no later than 2:00 PM to minimize insomnia 4, 1

• This provides a total daily dose of 40mg, which is the maximum FDA-approved dose 3
• The XR formulation provides approximately 12 hours of coverage 5
• The midday IR supplement addresses afternoon symptom breakthrough 1

Alternative if 40mg Total is Insufficient

If symptom control at 40mg total daily dose proves inadequate:

Morning dose: Adderall XR 30mg 1

Lunch dose: Adderall IR 15mg (no later than 2:00 PM) 4, 1

• This provides 45mg total daily, which some recent guidelines suggest as acceptable in adults (maximum 50mg) 1
• However, this exceeds the FDA label maximum of 40mg 3
• Document clearly that symptoms could not be controlled at 40mg or lower doses 6

Critical Timing Considerations

• Administer XR dose immediately upon awakening to ensure morning coverage 1, 3
• The IR lunch dose must be given before 2:00 PM to prevent insomnia 4, 1
• Late afternoon or evening doses should be avoided due to resulting insomnia 3

Important Monitoring Parameters

At each follow-up visit, assess:

• Blood pressure and pulse (check quarterly in adults) 1, 2
• Weight at every visit to monitor for appetite suppression 1, 2
• Target ADHD symptoms using standardized rating scales 1
• Side effects: insomnia, anorexia, headaches, mood changes, cardiovascular effects 1, 2, 7

Common Pitfalls to Avoid

• Do not exceed 40mg total daily dose without clear documentation that lower doses were ineffective 1, 2, 3
• Do not give the IR dose after 2:00 PM as this commonly causes insomnia 4, 1
• Do not crush, chew, or divide XR capsules as this destroys the extended-release mechanism 6
• Higher doses increase cardiovascular risks (hypertension, tachycardia) and potential for tolerance/dependence 2

If Maximum Dose Proves Ineffective

Rather than continuing to escalate beyond 40-50mg:

• Consider switching to an alternative stimulant medication (e.g., methylphenidate formulations) 1, 2
• Add environmental or psychosocial interventions 1
• Explore non-stimulant medication options (atomoxetine, guanfacine, clonidine) 2
• Reevaluate the diagnosis and consider comorbid conditions affecting treatment response 1

Food Effect Consideration

• Adderall XR absorption is significantly affected by high-fat meals, resulting in markedly lower early drug exposure 8
• Instruct the patient to take XR consistently either with or without breakfast to minimize day-to-day variation 8
• If taking with food, avoid high-fat meals as they reduce amphetamine concentrations over the first 8 hours 8