Published: 2 March 2023

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Use caution if switching between long-acting methylphenidate products due to formulation differences

Published: 2 March 2023
Prescriber Update 44(1): 13–14
March 2023

The Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom recently published advice for healthcare professionals to use caution if switching patients between long-acting methylphenidate products.¹ This article provides similar advice for New Zealand prescribers.

Methylphenidate

Methylphenidate is a central nervous system stimulant used for the treatment of Attention Deficit Hyperactivity Disorder (ADHD).² There are products with immediate-release and long-acting formulations available in New Zealand. Long-acting formulations are usually labelled as extended release, modified release, long acting (LA) or sustained release (SR).

The long-acting methylphenidate products available in New Zealand are Concerta, Methylphenidate Extended Release (Teva), Ritalin LA and Rubifen SR.

Formulation differences between long-acting methylphenidate products

Because the long-acting methylphenidate products are formulated differently, there is a need for caution when switching patients between products (brands).

Methylphenidate in long-acting formulations is released in two stages, due to the immediate-release and modified-release components.¹ Following oral administration, there is a rapid increase in plasma concentration reaching an initial maximum at about 1-2 hours. The plasma concentration then continues to increase more gradually until peak plasma concentration (C_max) is reached at about 6-8 hours.^2,3-5 The biphasic release profiles of different long-acting methylphenidate products may not be comparable due to formulation differences in the ratio of immediate release and modified release components.¹

Long-acting methylphenidate products may also differ in other ways, including the dose strengths available, mechanism of release, pharmacokinetics, plasma concentration-time profiles, bioavailability and whether the medicine is taken with or without food.¹

In addition, at the individual patient level, there is significant variability in the pharmacokinetic profiles of long-acting methylphenidate products throughout the day.⁶ Therefore, the patient’s response to any product or dosing regimen may vary substantially.⁶

Together, these differences may contribute to a change in clinical effect when long-acting products are used interchangeably. The same dose of different products may not necessarily be equivalent in terms of the clinical effect.

Communicate product (brand) changes to the patient, including reasons for the change, how to use the new medicine, possible changes they may experience in symptom management and potential side effects (and what to do if these occur).¹ Frequent switching between methylphenidate products is not recommended.¹

More information

See the sponsors’ data sheets and Consumer Medicine Information (CMI), published on the Medsafe website.

• Search for a methylphenidate data sheet or CMI

References

1. Medicines and Healthcare products Regulatory Agency. 2022. Methylphenidate long-acting (modified-release) preparations: caution if switching between products due to differences in formulations 26 September 2022. URL: gov.uk/drug-safety-update/methylphenidate-long-acting-modified-release-preparations-caution-if-switching-between-products-due-to-differences-in-formulations (accessed 16 January 2023).
2. Janssen-Cilag (New Zealand) Ltd. 2022. Concerta New Zealand Data Sheet 4 October 2022. URL: medsafe.govt.nz/profs/Datasheet/c/Concertatab.pdf (accessed 16 January 2023).
3. Teva Pharma (New Zealand) Limited. 2021. Methylphenidate Extended Release (Teva) New Zealand Data Sheet 2 June 2021. URL: medsafe.govt.nz/profs/Datasheet/m/methylphenidateTevatab.pdf (accessed 16 January 2023).
4. Novartis New Zealand Limited. 2022. Ritalin New Zealand Data Sheet 8 February 2022. URL: medsafe.govt.nz/profs/Datasheet/r/RitalintabSRtabLAtab.pdf (accessed 16 January 2023).
5. AFT Pharmaceuticals Pty Ltd. 2022. Rubifen New Zealand Data Sheet August 2022. URL: medsafe.govt.nz/profs/Datasheet/r/rubifentabsrtab.pdf (accessed 17 January 2023).
6. Coghill D, Banaschewski T, Zuddas A, et al. 2013. Long-acting methylphenidate formulations in the treatment of attention-deficit/hyperactivity disorder: A systematic review of head-to-head studies. BMC Psychiatry 13: 237. DOI: 10.1186/1471-244X-13-237 (accessed 17 January 2023).