Starting an opioid
Opioid analgesics are frequently needed by palliative care patients whose pain does not respond to simple analgesics, weak opioids, and other measures – see the NPS RADAR Prescribing Practice Review on this topic.
Persistent pain should be treated promptly. A high index of suspicion about the presence of pain is needed for patients who are unable to verbalise their experiences.
Morphine, oxycodone or hydromorphone are appropriate strong opioids to start. Caution should be used when initiating analgesia with fentanyl transdermal patches (Durogesic), particularly in the frail opioid naive patient.
Some analgesics are less suitable for use in palliative care, either because of their ceiling effect, their potential for drug interactions, or other problems (see Therapeutic Guidelines - palliative care 2nd edition p102-105) These include:
- Pethidine
- Tramadol (Tramal, Tramahexal, Tramedo, Zydol)
- Dextropropoxyphene (Capadex, Digesic, Paradex, Doloxene)
- Buprenorphine (Norspan, Temgesic)
- Dextromoramide.
Switching opioids
Reasons why opioid switching may sometimes be needed include:
- Renal failure
- Adverse effects thought to be due to a particular opioid
- Change in route of administration is required
- Problems with large volumes needing to be given subcutaneously.
Published guidelines for opioid conversion are based on estimates, and there is inter-individual variation. Different conversion factors may be favoured by different clinicians. Clinical judgement should always be used, and doses must be titrated to pain and side effects.
A useful Australian opioid conversion table from Calvary Health Care Bethlehem, can be downloaded. The IAHPC Manual of Palliative Care provides online guidance on equianalgesic doses and safe management of opioids.
The key to making changes in opioid analgesics is to review carefully and frequently about:
- Whether pain is adequately controlled after the change
- Side effects
- Whether pain is opioid responsive or requires additional pain management strategies.
Opioid non-responsive pain
Pain which is not responding to opioids should be reassessed, as the mechanism of the pain may suggest alternative analgesic strategies. The Palliative Medicine Handbook describes a helpful approach to this issue.
Finding out more
This page was created on 26 March 2007 and is due for review in March 2009
Last updated 21 July 2008