WHO Analgesic Ladder
This article discusses the WHO analgesic ladder for those who are unfamiliar with it and its use in practice.
Learning outcomes:
- to understand the basis of the WHO analgesic ladder
- to understand the concept of multimodal analgesia
WHO Analgesic Ladder
An analgesic is a member of the group of drugs which are used to relieve pain, also known as “painkillers”. The word analgesic derives from Greek an ("without") and algos ("pain").
The analgesic ladder was designed by the World Health Organisation (WHO) [1] to assist the healthcare prescriber in the prescription of analgesic drugs by suggesting a logical strategy for managing pain in a multitude of pain situations.
The ladder advocates a stepped approach to the use of painkillers from these analgesic groups:
- Simple analgesics i.e. paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs)
- Weak opioids i.e. tramadol, codeine
- Strong opioids i.e. morphine, fentanyl, oxycodone, pethidine
- Adjuvants - adjuvant analgesics are drugs which were not originally for pain but rather for other conditions but have been found to be effective in difficult to manage pain, particularly neuropathic pain. They are a diverse group of drugs that includes antidepressants, anticonvulsants (antiseizure drugs), and others.
At every step of the analgesic ladder non-opioid analgesics form the basis of the pain management. Paracetamol and NSAID (if not contraindicated) should always therefore be prescribed with opioid analgesia (weak or strong). This is known as multi-modal analgesia and is the concept that pain is best managed, not by a single drug or therapy, but by combinations, which maximise efficacy whilst keeping side-effects low. Evidence has demonstrated that when this happens pain relief is better, smaller amounts of pain killers are needed and less side effects occur.
Figure 1: WHO Analgesic Ladder
The WHO advocates that these analgesics should be given “by the clock”, that is every 3-6 hours, rather than “on demand.” This stepped approach of administering the right drug in the right dose at the right time is inexpensive and generally effective in managing acute pain.
The advantages of the analgesic ladder include:
- Simplicity, as only a few analgesic groups are used
- Flexibility to a large variety of pain situations and also to prescribers globally. By referring to drug classes, rather than specific drugs, the ladder maintains a level of flexibility that allows clinicians to work within their set regulations and limitations.
- Safety, in that safest drugs are used first in their lowest effective dose
- Emphasis on multimodal analgesia.
Its disadvantages include:
- It may be too simplistic for management of certain types of pain, especially neuropathic pain or for those who are opioid dependant.
- It suggests that analgesics should be administrated orally, which may occasionally not be appropriate, for example, when patients are 'nil by mouth'.
