WHO Analgesic Ladder
The Cancer Unit of the World Health Organization (WHO) developed the Analgesic ladder in 1986 in response to patients living in resource poor settings with advanced cancer and unlikely to undergo any preventative or curative treatments. WHO also made efforts to set up national cancer programs as a means of overcoming inadequate training of carers, overt fear of addiction, poor drug availability and a lack of public awareness. Another of its aims was the setting up of palliative and hospice care services, available to all patients with advanced illness.
Since its publication, the ladder approach has been extended to the management of acute and chronic non-malignant pain.
There are 5 guiding principles for its application which makes it a useful tool for teaching due to its simplicity may be summarised as:
- ‘By mouth’ – oral forms of analgesics is preferred wherever possible
- ‘By the clock’ – analgesic should be given at regular intervals rather than on demand.
- ‘By the ladder’ – The principles of the ladder should be adhered to.
- ‘For the individual’ – there is no standardised dosage and therapy and should be based around the level of the patient’s reported pain.
- ‘Attention to detail’ – refers to the close monitoring of the patient’s pain as well as the biopsychosocial factors that may be impacting upon their pain.
The analgesic ladder can be described as a three-step approach of sequential use of pharmacologic agents commensurate with the pain level as reported by the patient. Moving up from no treatment (see figure 1) the patient can be started on non- opioids (e.g. aspirin, paracetamol or non-steroidal anti-inflammatory drugs (NSAIDS)) for mild pain, then increasing to weak opioids like codeine and its derivatives for moderate pain and finally escalating to strong opioids like morphine, oxycodone, hydrocodone, methadone and fentanyl for the highest level of pain. WHO also mentions the need for adjuvant pharmacological agents such as muscle relaxants, anticonvulsants, antipsychotics, antidepressants, corticosteroids, anxiolytics and psychostimulants.
A note of caution should be mentioned that health care professionals need to read the guidelines in their entirety as they also mention ‘the relief of psychological, social and spiritual problems’ that constitutes the biopsychosocial model of care.
At every step of the analgesic ladder non-opioid analgesics form the basis of pain management. As long as they are not contraindicated, paracetamol, aspirin or an NSAID should also be prescribed with opioid analgesia (weak or strong). This is the concept that pain is best managed not by a single drug or therapy, but in combinations which maximise efficacy whilst keeping side-effects low. Research has demonstrated that when this happens, the synergistic effect on pain relief is improved, smaller amounts of pain killers are required and less side effects occur.
Controversies and limitations of the Ladder
- The evidence for NSAIDS in mild chronic pain and cancer pain is not as compelling as it is for acute mild pain.
- Renal, gastric and cardiac complications limits the long term use of NSAIDS.
- The value of step 2 is hotly debated questioning the use of weak opioids for cancer pain.
- Recent studies have demonstrated that weak opioids are not superior to full doses of NSAIDS calling into question step 2.
- The original ladder advises against the use of two or more agents on the same rung silmutaneously. Nowadays it is not unusual to see
- paracetamol prescribed in combination with an NSAID for mild, acute pain.
- For moderate to severe chronic or cancer pain it is not unusual to have a long acting opioid prescribed for background pain with a shorter acting opioid prescribed for breakthrough pain.
- If a patient is in severe pain they should be started from a drug for the treatment of severe pain and not with a drug from the bottom step.