Little gems: How hot are you on...pain management?
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This GEM covers aspects of pain management in palliative care. It is important for the primary care clinican to be aware of the various options for analgesia in palliative care management.
Q What is the 'pain ladder'?
A The concept of the pain relief 'ladder' is one that is used in palliative care:
Step one – non-opioid such as paracetamol, NSAID; Step two – weak opioid such as codeine +/- non opioid; Step three – strong opioid such as morphine +/- non-opioid.
The steps of the pain ladder are traversed one to three and the decision to go to the next step is based on whether pain persists or increases while at a particular step. The ladder has no 'top rung' as there is no maximum dose for strong opioids
Q What are examples of forms of analgesia used on step one and two of the pain ladder?
A Regular doses of simple analgesics or weak opiates will often make the use of strong opiates unnecessary. Examples of preparations that can be used on steps one and two of the 'pain ladder' include:
Step one preparations four- to six-hourly such as paracetamol 1g (maximum dose of 4g per day); Step two preparations
Weak opiates for use four- to six-hourly include:
• co-codamol 8/500 and 30/500 (opioid/paracetamol combinations)
• co-dydramol 10/500 and 20/500 (opioid/paracetaoml combinations)
• dihydrocodeine (DHC) 30mg (may be used concurrently with paracetamol)
• tramadol 50-100mg – total of more than 400mg per day not usually required (may be used concurrently with paracetamol)
Weak opiates for use 12-hourly include:
• DHC continus 60 and 120mg (may be used concurrently with paracetamol)
• tramadol SR 100-200mg (may be used concurrently with paracetamol)
Q Strong opioids, such as morphine, are used for moderate to severe pain. It is important the GP has knowledge regarding the relative potencies of different forms of opioid analgesia. If a person was taking the maximal dose of tramadol per day (400mg per day) then what dose of oral morphine would be approximately equivalent to the dose of tramadol?
• morphine total dose of 10mg per day
• morphine total dose of 100mg per day
• morphine total dose of 150mg per day
• morphine total dose of 200mg per day
A Tramadol 400mg per day is approximately equivalent to 100mg per day of morphine, ie tramadol has a potency rate of approximately a quarter of morphine mg to mg.
Q There is no upper limit for strong opiates in palliative care, but if the pain is not controlled despite rapidly escalating doses, then what causes should the GP consider?
A Causes to consider for failure of analgesia include:
• fracture or impending fracture
• hypercalcaemia, a common cause of
worsening bone pain
• urinary retention
• compliance: patients may dislike opiate owing to nausea, sedation, confusion, groundless fears or uncertainty as to the dose
• failure to absorb, eg vomiting
• neuropathic origin of pain
• new or other pathology, related or
unrelated to cancer such as angina
• depression or psychological distress
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