How should I transition from 5 mg immediate‑release Adderall (amphetamine/dextroamphetamine) to extended‑release Adderall XR?

Direct Conversion from Adderall IR 5mg to Adderall XR

Switch directly to Adderall XR 5mg once daily in the morning, as this provides equivalent total daily amphetamine exposure with extended coverage throughout the day 1.

Conversion Rationale

The FDA labeling confirms that Adderall XR and immediate-release Adderall contain identical amphetamine salt compositions in a 3:1 ratio of dextroamphetamine to levoamphetamine 1. The key pharmacokinetic principle is that Adderall XR 20mg once daily provides comparable plasma concentration profiles to Adderall IR 10mg given twice daily (4 hours apart) 1. This 2:1 conversion ratio applies across all dose strengths.

For your specific situation with 5mg IR:

• If taking 5mg IR once daily: Start Adderall XR 5mg once daily
• If taking 5mg IR twice daily (total 10mg/day): Start Adderall XR 10mg once daily

Pharmacokinetic Differences to Expect

The extended-release formulation uses a dual-bead delivery system that releases 50% of the dose immediately and 50% approximately 4 hours later 1. This creates important timing differences:

• Time to peak concentration (Tmax): XR reaches peak at ~7 hours vs. IR at ~3 hours 1
• Duration of action: XR provides approximately 12 hours of coverage vs. 4-6 hours for IR 2
• Onset: XR begins working within 1.5 hours, similar to IR 2

Practical Switching Instructions

1. Timing: Administer Adderall XR in the morning (typically upon waking) 1

2. Food considerations: Food delays peak concentration by 2-3 hours but does not affect total absorption 1. The medication can be taken with or without food based on tolerability.

3. Capsule administration options 1, 3:

   • Swallow capsule whole, OR
   • Open capsule and sprinkle contents on 1 tablespoon of applesauce (consume immediately without chewing)
   • Both methods provide equivalent bioavailability

4. No titration period needed: Switch directly on the next scheduled dose—no overlap or washout required.

Monitoring After Conversion

Assess symptom control at different time points during the day, particularly:

• Morning (hours 0-4): Should match or exceed IR effectiveness
• Afternoon (hours 4-8): May provide better coverage than single-dose IR
• Late afternoon/evening (hours 8-12): Extended benefit not present with IR

The extended duration is particularly valuable for adolescents who drive, as it provides symptom control during after-school activities and evening driving 4.

Common Pitfalls

• Expecting identical timing of effects: The delayed Tmax means peak effects occur later in the day. This is intentional and provides more sustained coverage rather than immediate peak effects.

• Afternoon IR supplementation: Some patients on other ER formulations require late-day IR supplementation 5, but this should not be assumed necessary at conversion. Evaluate need after 1-2 weeks of XR monotherapy.

• Dose stacking: Do not take additional IR doses "to bridge" the conversion. The XR formulation is designed to replace the entire daily IR regimen.