Amphetamine Dose Conversion: Adderall to Dexedrine
Adderall 30 mg IR BID (total 60 mg/day) converts to approximately Dexedrine 45 mg/day, divided into 2-3 doses.
Conversion Rationale
The conversion is based on the active amphetamine content in each formulation:
- Adderall contains a 3:1 ratio of dextroamphetamine to levoamphetamine salts 1, 2, 3
- This means Adderall 30 mg contains approximately 22.5 mg of dextroamphetamine and 7.5 mg of levoamphetamine 1
- Dexedrine contains only dextroamphetamine 4
Calculation Method
For Adderall 30 mg IR BID (60 mg total daily):
- Total dextroamphetamine content per day: 60 mg × 0.75 = 45 mg
- Total levoamphetamine content per day: 60 mg × 0.25 = 15 mg
The equivalent Dexedrine dose is 45 mg/day, as you are replacing only the dextroamphetamine component 1, 2.
Dosing Schedule Options
Option 1: Twice Daily Dosing
- Dexedrine IR 22.5 mg BID (morning and early afternoon) 4
- This mirrors the original Adderall schedule
Option 2: Three Times Daily Dosing
- Dexedrine IR 15 mg TID (morning, midday, early afternoon) 4
- May provide more consistent coverage throughout the day
Option 3: Spansule (Extended-Release) Formulation
- Dexedrine Spansule 15 mg in morning, plus 15 mg IR at midday, plus 15 mg IR early afternoon 4
- Or consider Dexedrine Spansule 30 mg once daily in morning if extended coverage is desired 4
Important Clinical Considerations
Potency Differences
- Patients may experience slightly different effects despite equivalent dextroamphetamine dosing because levoamphetamine has peripheral sympathomimetic effects that contribute to the overall clinical profile of Adderall 5
- Some patients report Dexedrine feels "cleaner" or has fewer peripheral side effects, while others prefer the mixed salts 1
Titration Approach
- Start with the calculated equivalent dose (45 mg/day) but be prepared to adjust by 5 mg increments weekly based on response 6, 7
- The 60 mg total daily Adderall dose exceeds the standard maximum recommendation of 40-50 mg/day 6, 8, so the equivalent Dexedrine dose of 45 mg/day also approaches upper limits
- Monitor closely for efficacy and side effects, as individual pharmacokinetic variability is substantial 3
Maximum Dosing Caution
- The maximum recommended daily dose for amphetamines is 40-50 mg/day 6, 8
- Your patient's current Adderall dose of 60 mg/day (containing 45 mg dextroamphetamine) is above standard recommendations 8
- If 45 mg/day of Dexedrine proves insufficient, consider alternative strategies rather than further dose escalation, such as adding behavioral interventions or switching medication classes 6, 8
Monitoring Parameters
- Assess blood pressure and pulse at baseline and with any dose adjustments 6, 7
- Monitor for common side effects including insomnia, anorexia, headaches, and weight loss 6
- Weigh patient at each visit to monitor for appetite suppression 6, 7
- Allow at least one week between any dose adjustments to properly evaluate response 6, 7
Common Pitfalls to Avoid
- Do not assume 1:1 conversion between Adderall and Dexedrine - this would result in overdosing 1, 2
- Avoid late afternoon or evening doses to minimize sleep disturbances 4, 6
- Do not continue escalating beyond maximum recommended doses if inadequate response occurs - instead reassess diagnosis and consider alternative treatments 6, 8
- Remember that approximately 70% respond to a single stimulant, but nearly 90% respond if both amphetamine and methylphenidate are tried 8, so consider methylphenidate if Dexedrine proves inadequate