Methylphenidate XR vs ER 24-Hour Formulations: Key Differences and Conversion
"XR" (Extended Release) and "ER" (Extended Release) are essentially interchangeable marketing terms used by different manufacturers for methylphenidate formulations, but the critical distinction lies in the specific delivery technology and duration of action—not the abbreviation itself. 1
Understanding the Terminology
The confusion arises because pharmaceutical companies use different abbreviations for similar concepts:
- "XR" and "ER" both refer to extended-release formulations that deliver methylphenidate over a prolonged period compared to immediate-release (IR) formulations 1
- Duration varies by specific product, not by whether it's labeled "XR" or "ER" 2
- Immediate-release methylphenidate lasts 3-4 hours, requiring multiple daily doses 3
Specific Formulation Differences
Different extended-release methylphenidate products have distinct pharmacokinetic profiles:
Morning-Predominant Formulations
- Metadate CD (MCD): Delivers 30% as immediate-release beads, then 70% as extended-release polymer-coated beads, providing superior morning coverage 4
- Ritalin LA: Similar biphasic delivery system 5
All-Day Coverage Formulations
- Concerta: Uses osmotic-release oral system (OROS) with 22% immediate overcoat and sustained release via osmotic pump, providing superior late afternoon/early evening coverage 4
- Duration approximately 10-12 hours 4
Novel Formulations
- Aptensio XR, Quillivant XR, QuilliChew ER: Various extended-release technologies with different pharmacokinetic profiles 2
- HLD-200 (Bejorna): Modified-release formulation designed for evening dosing 2
Dose Conversion Between Formulations
When converting between different methylphenidate extended-release formulations, use a 1:1 total daily dose conversion 4, 2:
Conversion Algorithm
- Calculate total daily methylphenidate dose from current formulation 6
- Convert 1:1 to the new formulation (e.g., 36 mg Concerta = 40 mg Metadate CD = 40 mg Ritalin LA) 4
- Start at equivalent dose or 10-20% lower if concerned about tolerability 6
- Titrate based on clinical response over 1-2 weeks 6
Practical Example
- Patient on Concerta 36 mg once daily (total daily dose = 36 mg)
- Convert to Metadate CD 40 mg once daily or Ritalin LA 40 mg once daily
- These are considered bioequivalent in total exposure 4
Converting from Immediate-Release to Extended-Release
- Sum total daily IR dose (e.g., 10 mg TID = 30 mg/day) 3
- Convert 1:1 to extended-release formulation (30 mg total daily IR = 30 mg extended-release once daily) 6, 4
Critical Clinical Considerations
Timing of Peak Effects Differs
- Metadate CD shows superiority in morning hours (1.5-4.5 hours post-dose) due to larger immediate-release component 4
- Concerta shows superiority in early evening (7.5-9 hours post-dose) due to sustained osmotic release 4
- Choose formulation based on when symptom control is most needed 4, 2
Common Pitfall to Avoid
Do not assume all "extended-release" formulations provide identical coverage throughout the day—the pharmacokinetic profiles differ substantially, and clinical effects vary by time of day 4, 2. A patient may respond differently to 40 mg Metadate CD versus 36 mg Concerta despite similar total exposure 4.
Monitoring Requirements
- Monitor blood pressure and heart rate when initiating or changing formulations 1
- Assess height and weight at baseline and regularly during treatment 1
- Evaluate efficacy at different times of day to ensure adequate coverage when needed 4
Maximum Dosing
- Maximum recommended daily dose is 60 mg regardless of formulation 6
- Individual response varies significantly; some patients require doses at different points in this range 3
Amphetamine to Methylphenidate Conversion
If converting from amphetamine-based medications (e.g., lisdexamfetamine/Vyvanse):