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.

Update history

  1. Title, URL and summary amended.
  1. Added bibliography
  1. Following internal QA check: text amended to better reflect wording in NICE guideline re: morphine being opioid of choice
  1. Published

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