The Cancer Pain Relief Programme of the WHO advocates a three-step ‘analgesic ladder’ in an attempt to improve the worldwide management of pain due to cancer (Figure 1).1
The underlying principle is that, following good pain assessment and thorough knowledge of a small number of analgesics, a simple approach should produce pain relief in the majority of patients.2 In essence, the approach combines two modalities of pain relief:1
- Non-opioid analgesics, such as NSAIDs or paracetamol, reduce inflammation and/or prostaglandin synthesis and thereby reduce nociceptive stimuli.
- Opioids reduce nociceptive transmission through inhibition at opioid receptors in the brainstem, spinal cord and perhaps peripheral nerves.
Opioids for mild-to-moderate pain are used in combination with a non-opioid analgesic, such as paracetamol, at the second step of the ladder. There are numerous combination step 2 analgesics available, however combinations may increase side-effects yet may not significantly increase efficacy.5
If regular maximum doses of opioids for mild-to-moderate pain do not achieve adequate analgesia, then they should be replaced with an opioid for moderate-to-severe pain, such as morphine.1
There is some debate as to whether the second step of the ladder adds value.2,4
One might argue it would make sense to simply add very small doses of strong opioids to non-opioids (for example, morphine 2.5mg). The added value of step 2 probably lies in the availability of these drugs worldwide rather than in superiority of effect.4 In moderate pain it is perfectly reasonable to commence small doses of strong opioids (licensed for moderate pain) without recourse to the ‘weaker’ opioids first.4,6
Although the WHO analgesic ladder was developed for use in cancer pain, a stepwise approach is probably equally applicable to the management of chronic pain due to other causes.2
1. WHO Pain Relief Ladder for cancer pain relief. Available at: www.who.int/cancer/palliative/painladder/en/ (accessed 14 April 2015).
2. Vargas-Schaffer G. Canadian Family Physician 2010;56(6):514–517, e202–205.
3. Azevedo São Leão Ferreira K, Kimura M, et al. Supportive Care in Cancer 2006;14(11):1086–1093.
4. Eisenberg E, Marinangeli F, et al. Time to Modify the WHO Analgesic Ladder? Pain: Clinical Updates 2005;13(5):1–4.
5. British National Formulary online March 2015. Available at: www.evidence.nhs.uk/formulary/bnf/current/4-central-nervous-system/47-analgesics/471-non-opioid-analgesics-and-compound-analgesic-preparations/compound-analgesic-preparations (accessed 14 April 2015).
6. Maltoni M, Scarpi E, et al. Supportive Care in Cancer 2005;13(11): 888–894.
Date of preparation: September 2015; MINT/PAEU-14003