Pain Flashcards
History of pain
SQITARS
Associated symptoms - breathlessness, bowels
Treatments already tried - frequency and dose
ICE
Features of pain in advanced disease
Persistent
Multiple aetiologies
Impairs function
Fear of cancer worsening
Causes of chest pain in cancer pateints
Cancer related - bone mets, invasion, malignant spinal cord compression
Treatment related - reaction to radiotherapy, oesophagitis, pneumonitis
Other medical conditions - Pneumonia, pneumothorax (biopsy), PE, MI, anxiety, MSK
Pathophysiology nociceptive pain
Caused by an identifiable lesion causing tissue damage which stimulates pain receptors in the normal nervous system
Features of somatic nociceptive pain
Sharp
Throbbing
Well localised
Pathophysiology of neuropathic pain
Caused by damage to the nervous system e.g. spinal cord compression
Pathophysiology of neuropathic pain
Caused by damage to the nervous system e.g. spinal cord compression
Features of visceral nociceptive pain
Diffuse ache
Difficult to localise
Features of neuropathic pain
Stabbing or shooting Burning Numbness or pins and needles Electric shock Hypersensitivity
Types of analgesics
Non- opiods
Adjuvants
Opiods
Examples of non-opiods
Paracetamol
Ibuprofen and other NSAIDs - diclofenac, naproxen
Examples of adjuvants
Anti - convulsant - Gabapentin, pregabalin
Antidepressants - Amitriptyline (TCA), duloxetine (SNRI)
Benzodiazepines - Diazepam, clonazepam
Bisphosphonates - for bone pain
Examples of opioids
Morphine Fentanyl Tramadol Oxycodone Dihydrocodeine
WHO analgesic ladder
- Non-opioid
+/- adjuvant - Opioid for mild/moderate pain
+/- non-opioid
+/- adjuvant - Opioid for moderate/ severe pain
+/- non-opioid
+/- adjuvant
COX2 NSAIDs and interactions
If there is no CV or GI risk - ibuprofen, diclofenac, naproxen
If there is a GI risk - COX 2 - celecoxib
If there is a CV risk - naproxen, ibuprofen
What is also prescribed with NSAIDs
PPI
When to give analgesics
Consider with pain that is only partially responsive to opioid analgesia
Opioid sparing effect
Drugs for neuropathic pain
Amitriptyline - prescribe at night
Gabapentin
Pregabalin
Advice for neuropathic pain medication
Takes at least 5 days for full benefit
May need further titration
Side effects of amitriptyline
Confusion
Sedation
Hypotension
Care with CVS disease
Side effects of pregabalin and gabapentin
Confusion Sedation Tremor Dizziness Care with renal impairment
WHO principles for analgesics
By mouth where possible By the clock rather than by pain By the ladder If adjusting SR, adjust PRN Use adjuvants at any step
Examples of 1st, 2nd and 3rd line analgesics
Step 1: Paracetamol and NSAIDs
Step 2: Dihydrocodeine, codeine phosphate, tramadol, co-codamol
Step 3: Oxycodone, morphine, fentanyl, diamorphine
Liver pain
Give dexamethasone to decrease inflammation
NSAIDs
Converting between codeine and morphine
10: 1 codeine: morphine
e. g. 240mg codeine = TDD 24mg morphine
Slow-release and PRN immediate-release morphine calculation
Slow release = TDD/ 2
PRN = TDD/ 6
Max number of PRN morphine doses in 24hrs
6
Immediate-release morphine
Oramorph liquid - 10mg/5ml
Slow-release morphine
Zomorph capsules BD
MST tablets BD - used for small doses
Take 12 hourly
Common side effects for opioids
Constipation - give laxative
Dry mouth
Nausea and vomiting - give anti-emetic
Drowsiness/ sedation - normally gets better and can drive if they feel fine
Opioids and respiratory distress
Check renal function as occurs with renal failure
Opioids and addiction
If used appropriately and at the right dose, it shouldn’t be a problem
Opioids and approaching the end of life
Often this slows the progression of deconditioning so there is a better quality of life
Fentanyl features
Transdermal patch
Non renally excreted
Takes 12 - 24 hrs to reach steady state
Fentanyl and morphine
12mcg/hour patch = 45mg TDD morphine
45/6 = 7.5mg - prescribe 8mg oramorph PRN
Syringe driver morphine
Delivered subcut - 1/2 24 hour oral dose
e.g. if 50mg zomorph BD = morphine 50mg/24hr via SCSD
Opioid toxicity presentation
Pinpoint pupils Hallucinations Drowsiness Vomiting Confusion Myoclonic jerks Respiratory depression
When does opioid toxicity present
If dose is escalated too quickly
Renal impairment - withhold zomorph and check renal function
Poor opioid responsive pain but escalated
Intervention to reduce pain such as nerve block and given opioid
Controlled drug prescription
- Name and ID of the patient
- Write prescription as normal
- Write supply and give pharmacist exact instructions
- Drug name and the formulation and strength
- Total no. of tablets in words and figures
