Methylphenidate IR to ER Conversion
When switching from methylphenidate immediate-release 5mg twice daily (total daily dose 10mg) to extended-release formulation, start with methylphenidate ER 10-18mg once daily in the morning, using the same total daily dose as the conversion baseline. 1, 2
Conversion Dosing Strategy
The total daily dose of immediate-release methylphenidate (10mg in this case) serves as the starting point for extended-release conversion, though you may need to adjust upward by approximately 20% to account for differences in bioavailability between formulations. 3, 4
For a patient on 10mg total daily IR dose, initiate OROS-methylphenidate (Concerta) 18mg once daily as the most appropriate starting dose, which provides 12-hour coverage and represents the closest available dose strength. 1, 3
Alternative ER formulations include Ritalin LA or Metadate CD 10-20mg once daily, though these provide only 8 hours of coverage compared to OROS-methylphenidate's 12-hour duration. 1, 4
Formulation Selection Considerations
OROS-methylphenidate (Concerta) is superior to older sustained-release formulations because it provides 12 hours of action with an early peak, while older SR formulations provide only 4-6 hours of clinical action with delayed onset and lower peak concentrations. 1
Newer extended-release formulations with bimodal delivery (early peak followed by sustained release) are clinically superior to older sustained-release products that fail to cover a full school or work day. 1, 4
For patients who cannot swallow tablets, microbead capsule formulations (Ritalin LA, Metadate CD) can be opened and sprinkled on applesauce without affecting the extended-release properties. 1, 5
Titration After Conversion
Assess response after 1 week at the initial ER dose, and if inadequate symptom control, increase by 18mg increments for OROS-methylphenidate (e.g., from 18mg to 36mg). 1, 2
Maximum daily dose should not exceed 60mg regardless of formulation, with dose adjustments based on symptom response using standardized rating scales and monitoring for side effects including tachycardia, insomnia, decreased appetite, and mood changes. 2, 3
Monitor blood pressure, pulse, and weight at baseline and regularly during titration, as these are critical safety parameters for stimulant therapy. 2
Clinical Advantages of ER Formulations
Long-acting formulations are associated with better medication adherence and probably lower risk of rebound effects compared to immediate-release formulations that create predictable plasma concentration troughs during unstructured times. 1
Switching from IR to OROS methylphenidate improves both adherence and effectiveness, with one study showing responder rates increasing from 28.6% with IR to 91.4% with OROS formulation, and 97% of patients preferring the ER formulation. 3
ER formulations eliminate compliance problems with in-school dosing, including school policies prohibiting medication administration, adolescent embarrassment/stigma, and forgetting afternoon doses. 1
Common Pitfalls to Avoid
Do not use older sustained-release formulations expecting full-day coverage, as they only provide 4-6 hours of clinical action despite being labeled as "sustained-release." 1
Avoid dosing ER methylphenidate after early morning to minimize insomnia risk; the single morning dose should provide coverage throughout the day without requiring afternoon supplementation. 1, 2
Do not assume exact dose equivalence between IR and ER formulations—some patients may require slightly higher total daily doses with ER formulations to achieve equivalent symptom control, though starting with the same total daily dose is appropriate. 3, 4