Important

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.


Alfentanil

Route Dose equivalent to 10mg oral morphine Comments
Parenteral 0.25 – 0.33mg (1,2,3)

Buprenorphine

Route Dose equivalent to 10mg oral morphine Comments
Sublingual 0.1 – 0.125mg (3,4) Higher doses sublingually are used for opiate dependence on specialist advice
Transdermal See table below

Codeine phosphate

Route Dose equivalent to 10mg oral morphine Comments
Oral 100mg (3,4) (Max single dose = 60mg)

Diamorphine

Route Dose equivalent to 10mg oral morphine Comments
Parenteral 3.33mg (1,2,3,4 )

Dihydrocodeine

Route Dose equivalent to 10mg oral morphine Comments
Oral 100mg (1,3,4) (Max single dose 60mg or 120mg MR) Doses above 30mg provide little extra analgesia but increase adverse effects

Fentanyl

Route Dose equivalent to 10mg oral morphine Comments
Transdermal See table below
Parenteral 0.067mg (1)

Hydromorphone

Route Dose equivalent to 10mg oral morphine Comments
Oral 1mg – 2mg (1,3,4) Potency if switching from hydromorphone to morphine is less than from morphine to hydromorphone
(switching from morphine to hydromorphone) Seek advice

Morphine

Route Dose equivalent to 10mg oral morphine Comments
Parenteral 3.33 – 5mg (1,2,3)

Oxycodone

Route Dose equivalent to 10mg oral morphine Comments
Oral 5 – 7.5mg (1,2,3,4)
Parenteral 3.33 – 5mg (1,2,3)

Pethidine

Route Dose equivalent to 10mg oral morphine Comments
Oral 80 – 100mg (1,3,4) Pethidine has duration of action of 2–3hours
Parenteral 25mg (1) Pethidine has duration of action of 2–3hours

Tramadol

Route Dose equivalent to 10mg oral morphine Comments
Oral 50 – 100mg (3,4,6) Tramadol’s pharmacology is complex. Extra caution required
Parenteral 25 – 50mg (6) Tramadol’s pharmacology is complex. Extra caution required

Tapentadol

Route Dose equivalent to 10mg oral morphine Comments
Oral 30mg (10,11) Switching from another µ agonist (e.g. morphine) may cause low-grade opioid withdrawal.

Buprenorphine Transdermal Dose Recommendations

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)

BuTrans® patch 5mcg/hr 10mcg/hr 20mcg/hr
Morphine oral 9-14mg per day 18-28mg per day 36-55mg per day

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)

Transtec® patch 35mcg/hr 52.5mcg/hr 70mcg/hr
Morphine oral 63-97mg per day 95-145mg per day 126-193mg per day

Fentanyl Transdermal Dose Recommendations

24-hour oral morphine dose mg/day (range) Equivalent fentanyl patch mcg/hour
30 12
60 (45-89) 25
90 37
120 (90-149) 50
150 62
180 (150-209) 75
240 (210-269) 100
300 (270-329) 125
360 (330-389) 150
420 (390-449) 175
480 (450-509) 200
540 (510-569) 225
600 (570-629) 250
660 (630-689) 275
720 (690-749) 300
Additional or alternative analgesia is required when fentanyl transdermal dose exceeds 300mcg/hr

References

  1. Back IN. Palliative Medicine Handbook 3rd ed. Cardiff:BPM Books. 2001
  2. Dickman A, Schneider J, Varga J. The Syringe Driver. 2nd ed. Oxford: Oxford University Press, 2005.
  3. Twycross R, Wilcox A. Palliative care formulary PCF3. 3rd edition 2007
  4. 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
  5. SPC for Oxynorm® (oxycodone) injection. Sept 2008.
  6. SPC for Zydol capsules/injection. March 2009
  7. SPC for Transtec® (buprenorphine)July 2009.
  8. SPC for BuTrans®(buprenorphine)March 2010
  9. SPC for Durogesic DTrans® (Fentanyl). September 2015. http://emc.medicines.org.uk/ (all SPCs may be accessed at this web address)
  10. Twycross R, Wilcox A. Palliative care formulary PCF3. 4th edition 2011
  11. 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
  12. Khanderia S (managing editor). British National Formulary. Accessed online via: http://www.medicinescomplete.com/mc/bnf/current/ on 26/08/2016
  13. 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

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