Principles of pharmacological management of pain in palliative care

Fallon, 2018Novy, 2020Wiffen, Derry, , 2017

This topic describes the use of analgesics for pain caused by advanced and progressive disease in the last year of life. It should be read in conjunction with the Principles of managing pain in palliative care topic, which defines the role of pharmacological therapy in the multidimensional approach to pain management.

Factors influencing choice of analgesic in palliative care describes the factors influencing choice of analgesic in patients with palliative care needs.

Figure 1. Factors influencing choice of analgesic in palliative care

Choice of analgesic for patients with palliative care needs depends on [NB1]:

  • pain severity
  • pain type(s) (nociceptive and/or neuropathic)
  • other symptoms requiring treatment (eg breathlessness, depression)
  • adverse effect profile of the drug; adverse effects may be more likely or more serious in patients with a progressive life-limiting illness
  • potential for drug interactions [NB2]
  • age- and disease-related changes in physiology, pharmacodynamics and pharmacokinetics (eg kidney or liver dysfunction)
  • comorbidities such as a history of chronic noncancer pain or disorders of substance use
  • route of administration; the oral route of administration is preferred unless the patient cannot take drugs orally or has impaired gastrointestinal absorption.

Analgesics are often required for extended periods; consider the practicality and long-term safety of the regimen (eg tablet burden, cost, access, risk of diversion). The potential for harm, particularly with opioids, must be balanced against the potential for improved function and quality of life.

Note:

NB1: For general factors that influence medication management in palliative care, see Principles of medication management in palliative care.

NB2: Obtain the patient’s complete medication list; they may be taking medications from multiple prescribers, over-the-counter medications, or complementary and alternative medications.

For mild to moderate nociceptive pain, particularly of soft tissue and musculoskeletal origin, paracetamol is the first-line analgesic because of its favourable safety profile at therapeutic doses.

If paracetamol is unlikely to provide adequate analgesia, a nonsteroidal anti-inflammatory drug (NSAID) can be used in addition to or instead of paracetamol. NSAIDs are useful for pain with an inflammatory component or bone pain. Monotherapy with an NSAID can be useful when tablet burden associated with paracetamol is a concern. However, NSAIDs can cause significant adverse effects and may not be appropriate—see Nonsteroidal anti-inflammatory drugs for pain in palliative care Derry, 2017Magee, 2019.

For moderate nociceptive pain, paracetamol and an NSAID may provide adequate pain management, but an opioid is often required, particularly if pain is expected to get worse.

For severe nociceptive pain or pain that does not respond to other measures, start opioid therapy as part of a multimodal approach to pain management.

For pain with a neuropathic component, early use of an adjuvant analgesic can improve pain management and may reduce opioid requirements.

Plan the pharmacological management of pain for when the patient cannot swallow or reaches the last days of life; subcutaneous administration of opioids may be required. See Switching opioids in palliative care for advice on switching opioids (including equianalgesic doses and switching routes of administration).

Additional considerations in the pharmacological management of pain are covered elsewhere for patients: