The below tables are an approximate guide only.
Opiate bioavailability and response are highly variable. Wide inter-patient variation exists.
Consider the need to adjust dose for conditions that increase opiate risk (eg elderly, co-morbidities, renal or hepatic impairment).
Where dose equivalence is expressed as a range, use the value that produces the lowest equivalent dose and titrate as necessary. Particular care is required when dealing with high doses of opiates.
The half life of the two drugs needs to be considered when converting so that the patient does not experience breakthrough pain or receive too much opiate during the conversion period.
Monitor the patient carefully for respiratory depression. Aim for a sedation score of <2 and respiratory rate >10/min.
If in doubt seek advice before prescribing.
When switching from an alternative opioid to BuTrans®, the manufacturer recommends starting with the lowest strength patch and using additional short-acting analgesia during titration, as required.(8)
The manufacturer of Transtec® recommends starting with the lowest strength patch. However, if the patient was already taking ≥120mg morphine orally or equivalent, the 52.5mcg/hr strength is suggested as the initial dose. (7)
- Back IN. Palliative Medicine Handbook 3rd ed. Cardiff:BPM Books. 2001
- Dickman A, Schneider J, Varga J. The Syringe Driver. 2nd ed. Oxford: Oxford University Press, 2005.
- Twycross R, Wilcox A. Palliative care formulary PCF3. 3rd edition 2007
- UKMi Medicines Q&As 42.4 What are the equivalent doses of oral morphine to other oral opioids when used as analgesics in adult palliative care. Oct 2009 http://nelm.nhs.uk
- SPC for Oxynorm® (oxycodone) injection. Sept 2008.
- SPC for Zydol capsules/injection. March 2009
- SPC for Transtec® (buprenorphine)July 2009.
- SPC for BuTrans®(buprenorphine)March 2010
- SPC for Durogesic DTrans® (Fentanyl). September 2015. http://emc.medicines.org.uk/ (all SPCs may be accessed at this web address)
- Twycross R, Wilcox A. Palliative care formulary PCF3. 4th edition 2011
- UKMi Medicines Q&As 42.6 What are the equivalent doses of oral morphine to other oral opioids when used as analgesics in adult palliative care. Sept 2011 http://nelm.nhs.uk
- Khanderia S (managing editor). British National Formulary. Accessed online via: http://www.medicinescomplete.com/mc/bnf/current/ on 26/08/2016
- Twycross R, Wilcox A, Howard P. Palliative care formulary PCF5. 5th edition 2014
This document has been produced with the most current literature available at the time of writing.
Produced by: Medicines Information, Cheltenham General Hospital
Updated: July 2011
Contacts: CGH MI 3030, GRH MI 6108
Ammendment to include Tapentadol June 2012
Fentanyl patch equivalence updated August 2016