Stimulant Equivalent Dose Conversion Table
For ADHD treatment, methylphenidate and amphetamine/dextroamphetamine preparations have a rough dose equivalency ratio of approximately 2:1 (methylphenidate:amphetamine), meaning 10 mg of methylphenidate is roughly equivalent to 5 mg of amphetamine or dextroamphetamine. 1, 2
Equivalent Dose Conversion Table
| Methylphenidate (MPH) | Dextroamphetamine/Amphetamine (DEX/AMP) | Clinical Notes |
|---|---|---|
| 5 mg | 2.5 mg | Typical starting dose for children [1] |
| 10 mg | 5 mg | Common initial therapeutic dose [1,3] |
| 15 mg | 7.5 mg | Low-moderate dose range [1] |
| 20 mg | 10 mg | Moderate dose range [2] |
| 30 mg | 15 mg | Upper-moderate dose range [2] |
| 40 mg | 20 mg | Higher dose range [4] |
| 54 mg (Concerta) | 27 mg | Equivalent to MPH 15 mg TID [1] |
| 60 mg | 30 mg | Maximum typical dose range [3,4] |
Key Dosing Principles
Starting Doses
- Methylphenidate: Begin at 5 mg once or twice daily for children; immediate-release formulations 1
- Amphetamine/Dextroamphetamine (Adderall): Begin at 5 mg once daily in early morning for adults, with noon dose added if needed 3
- Extended-release amphetamine: Start at 10 mg once daily in the morning 3
Titration Strategy
- Increase in 5-10 mg increments weekly for amphetamines based on symptom control and tolerability 3
- Titration can be accomplished in 7 days, or as rapidly as 3 days in urgent situations 1
- Continue titration until optimal symptom control is achieved without intolerable adverse effects 3, 4
Target Dose Ranges
- Methylphenidate: Most patients achieve optimal response at 20-60 mg total daily dose 1, 4
- Amphetamine/Dextroamphetamine: Most adults achieve optimal response at 40-60 mg total daily dose 3
- Maximum FDA-recommended doses: 40 mg for immediate-release amphetamine salts; 50 mg for extended-release formulations 3
Critical Conversion Considerations
Pharmacokinetic Differences
- Amphetamines have longer excretion half-lives than methylphenidate, resulting in greater effects on appetite and sleep 3
- Individual response is highly variable and unpredictable between stimulant classes, with approximately 43% of responders showing preferential response to only one stimulant formulation 2
- Dose response is not related to height or weight, so mg/kg calculations are not typically helpful 1
Response Rates Across Stimulant Classes
- 70% response rate when a single stimulant is tried in short-term trials 1, 5
- More than 90% of patients will respond to one of the psychostimulants if a range of medications from both methylphenidate and amphetamine classes are tried 1
- Failure to respond to one medication does not predict failure to another, as the three major stimulants have somewhat different mechanisms of action 6
Dose-Response Relationship
Efficacy Patterns
- Flexible-dose trials demonstrate increased efficacy with increasing doses across the entire FDA-licensed range for both methylphenidate and amphetamine 4
- Fixed-dose trials show incremental benefits decrease beyond 30 mg of methylphenidate or 20 mg of amphetamine, but this may underestimate true potential benefit in clinical practice 4
- Effect sizes range from 0.8 to 1.0 SD on teacher reports for both methylphenidate and dextroamphetamine 1, 5
Tolerability Patterns
- Fixed-dose trials show increased likelihood of discontinuation due to adverse events with increasing doses 4
- Flexible-dose trials show reduced likelihood of discontinuation for any reason with increasing doses, because practitioners can adjust based on response and tolerability 4
- Decreased appetite and insomnia are more common at higher dose levels for both stimulants 2
Common Pitfalls in Dose Conversion
Avoid These Errors
- Do not assume linear dose equivalency across all dose ranges—individual titration is essential despite the 2:1 ratio guideline 2
- Do not use the same total daily dose when switching formulations—extended-release preparations may require different dosing strategies than immediate-release 1
- Do not continue escalating dose when symptom control plateaus—consider switching medication classes rather than pushing to maximum doses 3
- Do not calculate doses based on mg/kg—variations in dose response are not related to body weight 1
Monitoring Requirements During Conversion
- Obtain baseline blood pressure, pulse, height, and weight before initiating any stimulant 3
- Monitor blood pressure and pulse at each dose adjustment during titration 3
- Collect symptom ratings before each dose increase and systematically assess for side effects 3
- Use standardized ADHD rating scales to objectively track response during conversion 3
budget:token_budget Tokens used this turn: 5481 Tokens remaining: 194519