Pain management Flashcards
What analgesics to prescribe a palliative patient when starting treatment?
names, doses + adjuvants
- oral modified-release (MR) or oral immediate-release morphine
- oral immediate-release morphine for breakthrough pain
- use 20-30mg of MR a day with 5mg morphine for breakthrough pain
- laxatives should be prescribed
- patients should be advised that nausea is often transient. If it persists then an antiemetic should be offered
- drowsiness is usually transient - if it does not settle then adjustment of the dose should be considered
What’s the dose of breakthrough morphine?
the breakthrough dose of morphine is one-sixth the daily dose of morphine
What are the preferred opioid options for a patient with renal failure
- oxycodone → if renal failure is not severe
- fentanyl/ alfentanil or buprenorphine → in severe renal failure
How can metastatic bone pain be managed?
- strong opioids
- bisphosphonates
- radiotherapy
- denosumab (monoclonal antibody RANKL inhibitor)
* NSAIDs are not particularly effective for metastatic bone pain
How much should we increase to dose by when increasing the opioids?
When increasing the dose of opioids the next dose should be increased by 30-50%.
Convert oral codeine to oral morphine
oral codeine → oral morphine
Divide by 10
Convert oral tramadol to oral morphine
oral tramadol → oral morphine
Divide by 10
What are the advantages of use of oxycodone instead of morphine?
Oxycodone generally causes:
- may be used in renal failure (unless severe)
- less sedation, vomiting and pruritis than morphine
*but oxycodone causes more constipation
Convert oral morphine to oral oxycodone
oral morphine → oral oxycodone
Divide by 1.5 - 2
How much of transdermal fentanyl equals oral morphine?
transdermal fentanyl 12 microgram patch equates to approximately 30 mg oral morphine daily
How much of transdermal buprenorphine equals oral morphine?
transdermal buprenorphine 10 microgram patch equates to approximately 24 mg oral morphine daily
Convert oral morphine to SC morphine
oral morphine to SC morphine
divide by 2
in which units do we have alfentanil doses?
micrograms
Examples of ‘adjuncts’ to analgesics (classes)
Adjuvants → drugs that are not technically analgesics but may relieve pain resistant to conventional analgesics
- anti-depressants e.g. neuropathic pain (as acting on descending tract)
- anti - spasmodic (smooth muscle relaxants)
- selective anti-inflammatory drugs e.g. Coxibs
- corticosteroids
- anti-convulsants
- skeletal muscle relaxants
- bisphosphonates
- NMDA-receptor blockers
Examples, MoA and advantage of selective anti-inflammatory drugs
‘Coxibs’
MoA: inhibit COX2
Examples: Celacoxib, Etoicoxib
What’s used for muscle spasms? (2)
benzodiazepines, baclofen
What are (2) 4th line drugs for neuropathic pain?
Ketamine and Methadone
- both work on NMDA receptors (block them)
- only specialist use
Meaning of 123ABC
123 - WHO analgesic ladder
ABC - adjuncts, bowel, co-fctors
WHO analgesic ladder
1. Non-opioid (e.g. NSAIDs, paracetamol)
2. Weak opioids (e.g. codeine, tramadol, dihydrocodeine) + paracetamol
3. Strong opioids (e.g. morphine, fentanyl, buprenorphine) + paracetamol
What’s meant by A (in 123 ABC)?
Adjuvants: e.g. anti-inflammatory, steroids, anti-epileptics, anti-depressants ⇒ to further manage pain
What’s meant by B in 123 ABC?
B - bowels
- prevent constipation
- gastric protection PPI (if needed)
- anti-emetics for sickness
What’s meant by C in 123 ABC?
C - co-factors
- non- pharmacological management
- holistic approach
All extras for pain management ‘CHAIRS’
C - chemotherapy
H - hormones
A - regional analgesia
I - immunotherapy
R - radiotherapy
S - surgery
Types of opioid receptors?
- mu
- delta
- kappa
- ORL-1 (opioid like receptor_)
work by:
opioid + receptor → G protein activated → effect via 2nd messager
