Pain Management Flashcards
How might someone describe neuropathic pain?
Stabbing
Shooting
Stinging
Burning
How might someone describe nociceptive somatic Pain?
Sharp
Throbbing
Well localised
How might someone describe nociceptive visceral pain?
Diffuse ache, difficult to localis
Outline the WHO pain ladder
Step 1: non-opioid e.g. aspirin, paracetamol +/- adjuvant
Step 2: weak opioid e.g. codeine, dihydrocodeine, tramadol +/- non-opioid +/- adjuvant
Step 3: strong opioid e.g. morphine, diamorphine, oxycodone, fentanyl, alfentanil +/- non-opioid +/- adjuvant
What is the standard adult dosing regime for paracetamol?
1g TDS
When should you consider reducing paracetamol dose to 500mg TDS?
Poor nutrition status
Weight < 50kg
Hepatic impairment
Chronic alcohol abuse
What is celecoxib and why would you prescribe it?
COX-2 selective inhibitor
To avoid ADRs - mainly GI (stomach pain, nausea, heartburn, ulcers) in patients at risk of these side effects
What cautions do you need to think about when prescribing NSAIDs?
GI ADRs - prescribe PPI
Renal Disease - NSAIDs reduce prostaglandins causing reduced GFR
Hepatic Disease
Heart failure
What is the maximum daily dose of codeine?
60mg QDS or 240mg/24hrs
What is the conversion ratio for codeine:morphine?
10:1
How much morphine is equivalent to 240mg of codeine?
24mg morphine
What would you generally prescribe to step up to rung 3 of the opioid ladder?
Morphine SR 15mg BD
Morphine IR 5mg PRN for breakthrough pain
Why should paracetamol be continued at steps 2 and 3?
It may have an opiate sparing effect
When might you consider starting with lower doses?
Frail, elderly
Renal impairment
What types of pain responds poorly or partially to opioids?
Neuropathic
Bone
What should prescribe alongside strong opiates?
Regular anti-emetic e.g. metoclopramide or haloperidol
Regular laxative e.g. Senna, Macrogol
What are the side effects of morphine?
Constipation Morphine Drowsiness Dry mouth Renal impairment Respiratory depression
How do you work out new doses of Zomorph and oromorph from TDD?
TDD / 2 = Zomorph BD
TDD / 6 = Oromorph PRN
What are the second line opioids?
Oxycodone
Fentanyl
What is the dose ratio of morphine:oxycodone?
2:1
So oral morphine 60mg = oral oxycodone 30mg = SC oxycodone 15mg
SC morphine 30mg = SC oxycodone 15mg
What is fentanyl?
A potential opioid analgesic in a topical patch that lasts 72 hours
How long does a fentanyl patch take to have an effect?
12-24 hours
What is the smallest fentanyl patch available?
12 mcg
What dose of oral morphine is a 12mcg fentanyl patch equivalent to?
45mg/24hr
For what patients is alfentanil particularly suitable?
In stage 4-5 CKS or severe renal impairment
What is an ‘adjuvant’ pain medication?
A drug whose primary indication is for something else other than pain.
List some common adjuvants and the type of pain they can be used for.
NSAIDs - bone pain, liver pain, inflammatory pain
Antidepressants e.g. amitriptyline- neuropathic pain, helps sleep
Anticonvulsants e.g. gabapentin - neuropathic pain
Benzodiazepines
Steroids- liver capsule pain, neuropathic pain
Bisphosphonates - bone pain
How do you convert oral morphine to SC morphine?
Half the dose
Oral morphine 30mg = SC morphine 15mg
