Switching between morphine and other opioids in palliative care

Published 14 September 2021Last updated 5 October 2021See all updates

Topics: Anaesthesia and painCancersCodeine · 8 more DihydrocodeineHydromorphoneMorphineOxycodonePalliative and End of Life CareSwitchingTapentadolTramadol · Less

Switching between oral morphine and other oral opioids requires care and thoughtful application of a stepped process.

Reasons for switching

NICE Clinical Guideline 140: Palliative care for adults: strong opioids for pain relief recommends oral morphine as the first-line strong opioid for maintenance treatment of pain in palliative care patients with advanced and progressive cancer, so prescribers may wish to switch from other opioids to morphine.

In some cases, however, other opioids may be preferred to morphine. For example, if a patient isn’t getting sufficient pain relief with morphine or is suffering from, or is at risk of, side effects.

Scope of our advice

Our advice only applies to opioids prescribed for oral administration in adults for pain management in palliative cancer care settings. We cover dosing equivalences only, rather than choice of opioid.

If your opioid conversion is outside this scope, you should consult national or local guidelines, or seek advice from a relevant specialist service, or contact our medicines advice service.

Other information sources

In addition to our tool, healthcare professionals may come across several information sources (e.g. websites, journal articles, reference books etc) offering guidance on opioid dose equivalences. Make sure the information sources you use are reliable and applicable to your clinical scenario.

You may need to look in a few places to find information on dose equivalences before making a clinical judgement on what dose to prescribe for an individual patient.

You should bear in mind that dose equivalences are always an approximate guide only, because we don’t have a great deal of precise data.

Information sources may differ in the equivalent doses they quote and there will also be variation between individuals.

Apply a stepped process when switching

Applying the stepped process outlined below will support you in making a safe switch for your patient.

Seek specialist advice

Whenever possible seek advice from a palliative care or pain specialist before switching opioids.

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A NICE Clinical Knowledge Summary on Palliative Cancer Care – pain advises primary care healthcare professionals to “Seek specialist advice or consult local guidelines (where available) when selecting the opioid and dose to switch to. This is because experience in primary care is likely to be limited and alternative oral opioids are best initiated by a person with experience in palliative care.”

It is important to consider other strategies if people are suffering from, or are at risk of, side effects, such as:

non-pharmacological pain relief
reducing the opioid dose (and possibly adding adjuvant analgesics)
symptomatic management of the side effect, or
switching the route of administration.

You may also find information on switching opioids and dose equivalences in specialist palliative care reference sources, such as The Palliative Care Formulary (subscription required), or in national or local palliative care guidelines, such as the Scottish Palliative Care Guidelines: Choosing and Changing Opioids

Consult manufacturer's information

As with any prescribing situation, it's important to check the manufacturer's information and advice and ideally to follow their guidance.

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For official manufacturer’s information, the best place to look would be the Summary of Product Characteristics (SmPC) for the opioid analgesic the patient will be switching from or to, not the morphine SmPC. SmPCs for most opioid analgesics provide information on dose equivalences or potency to morphine. The SmPC may also provide specific advice on prescribing for patients who have been taking morphine or other opioid analgesics.

You can find SmPCs for most medicines on the eMC or MHRA websites. The information on dose equivalences or switching will usually be in section ‘4.2 Posology and Method of Administration’ or ‘5.1 Pharmacodynamic effects’.

Use our tool

If you haven't found the information you need, or want to double-check, you can use our tool to help you calculate an approximate dose to switch to.

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Follow further steps below.

Calculate current total daily dose

Include all opioids the patient currently takes

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The total daily dose of the current opioid(s), including all long-acting and breakthrough doses, must be determined prior to conversion. If the patient is on multiple opioids, convert all to morphine equivalents.

Estimate an equivalent dose

Identify an approximate potency equivalence using our tool

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Use our tool to identify the approximate potency equivalence, and follow the directions given in the tool to calculate an equivalent morphine or non-morphine opioid dose.

Consider applying a dose reduction

Experts often advise reducing the calculated dose of the new opioid to ensure safety.

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The usual starting point is to reduce the calculated dose of the new opioid by 25 to 50%.

But you will need to consider individual patient factors to decide whether or not to apply a dose reduction.

High risk patients

A dose reduction is particularly important when:

using high doses
people are at increased risk from opioids (e.g. older, frail patients or those with co-existing medical conditions)
people have not tolerated or have had side effects with the opioid they are switching from
there has been a rapid dose escalation of the opioid being switched

In these cases a dose reduction of at least 50% would be recommended.

Low risk patients

Dose reduction may not be necessary in younger patients with no other medical conditions or for patients taking low doses.

Patients with severe pain

In cases where the original opioid has failed to control pain or if the individual is experiencing severe pain, it may be better not to reduce the dose and to prescribe the calculated equivalent dose.

Double-check your calculation and plan

Be careful when converting to avoid either under-dosing or excessive dosing; check your plan

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Consider the following:

Ask a colleague to double-check your calculations.
Seek specialist advice
Seek advice from where you obtain your medicines information service from

Prescribe as required opioids

Ensure immediate-release opioids are available for management of breakthrough pain

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Patients on a regular strong opioid should also have an opioid prescribed ‘as required’ (‘prn’) for breakthrough pain. These should not be modified-release preparations.

Scottish Palliative Care guidelines suggest an appropriate ‘prn’ dose is typically one-sixth to one-tenth of the regular opioid dose.

Refer to the relevant SmPC or BNF for further prescribing advice (e.g. dose intervals, frequency, maximum doses etc).

Monitor patients and titrate doses

Once converted, the dose of new opioid should be titrated carefully either up or down according to individual response. The ‘prn’ dose for breakthrough pain may also need to be adjusted.

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A NICE Clinical Knowledge Summary on palliative cancer care – pain provides advice on titrating oral morphine doses.

NICE guidelines advise that patients will need frequent review, particularly in the titration phase, to make sure their pain is adequately controlled and they do not suffer serious side effects. Specialist advice may be needed if, after a few dose adjustments, a good balance between pain control and side effects is not reached.

Make sure patients and family or carers are advised of the signs and symptoms of opioid overdose (drowsiness, shallow breathing, pinpoint pupils) and know they need to seek immediate medical help if they occur.

Bibliography

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1. Caraceni A, Hanks G, Kaasa S et al for the European Palliative Care Research Collaborative (EPCRC), on behalf of the European Association for Palliative Care (EAPC). Use of opioid analgesics in the treatment of cancer pain: evidence-based recommendations from the EAPC. Lancet Oncol 2012;13:e58-68.

2. Twycross R, Wilcock A (eds).Strong opioids monograph. Updated August 2020. Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 12th November 2020.

3. Slatkin NE. Opioid switching and rotation in primary care: implementation and clinical utility. Curr Med Res Opin 2009;25(9);2133-2150.

4. Fine PG, Portenoy RK. Establishing “best practices” for opioid rotation: conclusions of an expert panel. J Pain Symptom Manage 2009;38(3):418-425.

5. Nuckols TK, Anderson L, Popescu I et al. Opioid prescribing: A systematic review and critical appraisal of guidelines for chronic pain. Ann Intern Med 2014;160:38-47.

6. Twycross R, Wilcock A (eds). Opioid dose conversion ratios monograph. Updated August 2017. Palliative Care Formulary. Accessed via via https://www.new.medicinescomplete.com on 12th November 2020.

7. Twycross R, Wilcock A (eds). Weak opioids monograph. Updated November 2020. Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 14th January 2021

8. Twycross R, Wilcock A (eds). Codeine phosphate monograph. Updated November 2020. Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 14th January 2021.

9. Wessex and ASWCS Palliative Physicians. The Palliative Care Handbook. Advice on clinical management. 9th Edition 2019. Accessed online via https://westhampshireccg.nhs.uk/ 12th November 2020

10. Regnard C, Dean M (eds). A Guide to Symptom Relief in Palliative Care 6th edition. Radcliffe Publishing. Oxford; 2010:67.

11. Pain management with opioids. Joint Formulary Committee. British National Formulary. London: BMJ Group and Pharmaceutical Press. Accessed via https://www.new.medicinescomplete.com on 7th December 2020

12. Twycross R, Wilcock A (eds). Dihydrocodeine tartrate monograph. Updated November 2020. Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 14th January 2021

13. Twycross R, Wilcock A (eds). Hydromorphone monograph. Updated November 2020. Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 14th January 2021

14. SPC Palladone (hydromorphone) capsules. Napp Pharmaceuticals Ltd. Accessed via http://www.medicines.org.uk/emc/ on 12th November 2020 (SPC last updated on eMC 8th October 2020)

15. Twycross R, Wilcock A (eds). Morphine monograph. Updated August 2016. Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 14th January 2021..

16. Twycross R, Wilcock A (eds). Oxycodone monograph. Updated April 2020. Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 17th November 2020..

17. SPC OxyNorm (oxycodone) 5, 10, 20mg. Napp Pharmaceuticals Ltd. Accessed via http://www.medicines.org.uk/emc/ on 10th November 2020 (SPC last updated on eMC 16th July 2020)

18. SPC Oxylan 5mg, 10mg, 20mg, 40mg, 80mg prolonged release tablets. Healthcare Pharma Ltd. Accessed via http://www.medicines.org.uk/emc/ on 10th November 2020 (SPC last updated on eMC: 14th April 2020)

19. SPC Longtec 5mg, 10mg, 15mg, 20mg, 30mg, 40mg, 60mg, 80mg and 120mg prolonged release tablets. Qdem Pharmaceuticals Ltd. Accessed via http://www.medicines.org.uk/emc/ on 10th November 2020 (SPC last updated on the eMC: 21st July 2020)

20. Twycross R, Wilcox A (eds) Tapentadol monograph. Updated November 2020. Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 14th January 2021

21. Personal communication, Medical Information department Grünenthal Ltd. 22nd September 2016.

22. Twycross R, Wilcock A (eds). Tramadol monograph. Updated November 2020 Palliative Care Formulary. Accessed via https://www.new.medicinescomplete.com on 14th January 2021.

23. SPC Zydol 50mg capsules. Grünenthal Ltd. Accessed via http://www.medicines.org.uk/emc/ on 12th November 2020 (SPC last updated on eMC: 10th September 2020)

24. Vissers KCP, Besse K, Hans G et al. Opioid rotation in the management of chronic pain: where is the evidence? Pain Practice 2010;10(2):85-93.

25. Berdine HJ, Nesbit SA. Equianalgesic dosing of opioids. J Pain Palliat Care Pharmacother 2006;20:79-84.

26. Pereira J, Lawlor P, Vigano A et al. Equianalgesic dose ratios for opioids: a critical review and proposals for long-term dosing. J Pain Symptom Manage 2001;22:672-687.

27. Anderson R, Saiers JH, Abram S et al. Accuracy in equianalgesic dosing: conversion dilemmas. J Pain Symptom Manage 2001;21:397-406.

Update history

22 March 2024

Title, URL and summary amended.

5 October 2021

Added bibliography

24 September 2021

Following internal QA check: text amended to better reflect wording in NICE guideline re: morphine being opioid of choice

14 September 2021

Published

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SPS - Specialist Pharmacy Service

NHS

Switching between morphine and other opioids in palliative care

This article forms part of a series

Contents

Reasons for switching

Scope of our advice

Other information sources

Apply a stepped process when switching

Seek specialist advice

Consult manufacturer's information

Use our tool

Calculate current total daily dose

Estimate an equivalent dose

Consider applying a dose reduction

High risk patients

Low risk patients

Patients with severe pain

Double-check your calculation and plan

Prescribe as required opioids

Monitor patients and titrate doses

Bibliography

Update history

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