WHO analgesic ladder Flashcards
What meds can be given on step 1 of the WHO ladder?
Non-opioids:
Paracetamol
NSAIDs
How does paracetamol work?
No one knows
Mild analgesic, antipyretic properties
How do NSAIDs work?
Mild analgesics with anti-inflammatory effect
What meds can be given on step 2 of the WHO ladder?
Weak opioids
Codeine
Tramadol
How does codeine work?
Conversion in the liver to morphine- normally 10%
What can codeine be used for?
Analgesia, cough suppression, anti-diarrhoeal
What are common side effects of codeine?
Constipation
Drowsiness
Rash
How does tramadol work?
Complex MOA. Binds u-opioid receptors, inhibits reuptake of 5-HT and NA
What are side effects of tramadol?
Less constipating than codeine
Respiratory depression
Small risk of serotonin syndrome when combined with other CNS drugs
What meds can be given on step 3 of the WHO ladder?
Potent opioids Morphine Oxycodone Fentanyl Diamorphine
Prescribe both regular (sustained release) and PRN (immediate release) for chronic conditions
Prescribe PRN for short term e.g. nephrolithiasis
What is the normal starting dose of morphine?
20-30mg per day
If needing >2 doses of morphine for breakthrough pain in 24 hours, increase background amount
What are common SEs of morphine?
Constipation
Nausea
Vomiting
Dry mouth
Prescribe prophylactic laxative- faecal softener ± stimulant
What is oxycontin?
Sustained release oxycodone
What is oxynorm?
Immediate release oxycodone
What are the side effects of oxycodone
Less constipating
More sedating
How does fentanyl work?
Synthetic opioid 200x more potent than morphine
How is fentanyl given?
Patch- 72 hours of continuous release
What may change fentanyl release?
Exposure to external heat-increases
Where is diamorphine used?
Palliative care primarily due to low injection volume
Less nausea and hypotension
How is dosing different in palliative care?
No maximum dose
Look at start of BNF
How does administration of drugs change in palliative care?
Often need to change route of administration with time- need to convert correctly
PO morphine to IM or SC need to half the dose
What is the conversion between oral morphine and SC diamorphine?
Divide dose by 3
What opiates are controlled prescription drugs?
Morphine
Diamorphine
Oxycodone
Fentanyl
What opiates are not controlled prescription drugs?
Codeine
Tramadol
Dihydrocodeine
Diazepam
