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How to prescribe analgesia (the WHO pain ladder)


  • Analgesia prescribing can be complex; below is a simple framework that can help. It may be helpful to read pages on the assessment of pain first.
  • Prescribing in pain should always follow the WHO analgesic ladder.
    • Follow this ladder and start with simple analgesia if the patient has not already tried this
    • The basic steps of the WHO pain ladder are:


Step 1

  • For mild to moderate pain, start with a nonopioid (e.g. paracetamol and ibuprofen)
    • Prescribe: paracetamol 1g QDS regularly and ibuprofen 400mg TDS as required
    • Increase the dose, if necessary, to the maximum recommended.
    • Watch liver function with paracetamol
    • Avoid NSAIDS if renal impairment or history of GI ulcers and use with caution in the elderly. Give PPI (e.g. lansoprazole 30mg OD) if regular use.
  • Consider using an adjuvant anti-depressant or anticonvulsant if there may be a neuropathic element (e.g. Amitriptyline 10mg ON)
  • If the patient presents with moderate or severe pain, complete step 1 and move straight to step 2


Step 2

  • If or when non-opioids do not adequately relieve pain, add a weak opioid
    • Note that step 1 agents (paracetamol +/-  ibuprofen) should be continued with the weak opiod
  • The usual weak opiod is codeine
    • Prescribe: codeine phosphate 30-60mg QDS as required
    • Remember to consider a laxative (e.g. sodium docusate 200mg BD) and antiemetic (e.g. metoclopramide 10mg TDS as required) when prescribing any opiod
  • Add or continue neuropathic adjuvants, if appropriate


Step 3

  • If or when the non-opioid for mild to moderate pain no longer adequately relieves the pain, switch to a strong opioid (e.g. morphine, oxycodone).
    • An initial prescription could be: morphine 2.5-5mg orally every 2 hours are required.
      • Monitor for signs of overdose and prescribe naloxone (200-400mcg when required) if you are concerned the patient is at high risk of overdose
    • Continue paracetamol +/- ibuprofen alongside the morphine
    • Add or continue adjuvants, if appropriate
    • STOP THE CODEINE IF MOVING TO STEP 3 (do not use a weak opiod and a strong opiod at the same time)
  • At all steps continue adjuvants (e.g. amitriptyline/gabapentin), especially if there is a neuropathic component, and consider non-pharmacological treatments (e.g. psychology input, TENS machines etc.)


Tips on analgesia prescribing

  •  Remember is someone is already taking large amounts of opiates they probably will not thank you for suggesting paracetamol!
  • Try to avoid starting more than one type of analgesia regularly as you will not know which drug has worked.
  • Always ensure that the patient has as required (PRN) analgesia prescribed in case they are in pain before they see you again.
    • Tell the nursing staff to contact a doctor if the patient needs more than 2x PRN in a 24 hour period. If this is the case, then this either suggests that the regular dose may need to be titrated up quickly or that the drug is not working at all.
  • If your patient is still in pain consider if they are absorbing the medication properly? Consider this in patients with vomiting, bowel obstruction or faecal loading and switch to a sc/iv route.
  • At every step of the ladder, consider an adjunct: introducing a different type of analgesia in addition e.g. neuropathic agent added to opioid is often very effective
  • Always consider exploring non-pharmacological methods, especially in patients who are anxious or very distressed.
    • Examples range from using TENS (transcutaneous electrical nerve stimulation) machines to massage and art therapy.


Click here for how to prescribe morphine and other opioids 

Perfect revision for medical students, finals, OSCEs and MRCP PACES

Click here for managing morphine overdose (opioid toxicity)


Click here to download free teaching notes on Types of analgesia and how to prescribe it