Pain In Cancer Management Flashcards
WHO analgesia guidelines:
- By mouth
- By the clock
- By the ladder
Analgesia administration routes
PO, Transdermal SC Sublingual (If eliminated first pass) Rectal Inhaled:methoxypenthol Topical Intranasal Epidural Intrathecal Ventrcularly
Which Meds wiped out first pass metabolism?
Bupremorphine
Fentanyl
When move away from oral route?
Dysphagia
Gastric Tumours
Bowel obstruction
Fentanyl used when?
Kidney failure
Older individuals
Morphine orally lasts how long? (Non extended release)
4 hours
Ladder of analgesia
1st rung: simple analgesia, NSAIDS
2nd: weak opiates: codeine, tramadol, tapentadol
3rd: strong opiates: morphine, fentanyl, hydromorphine(strongest), oxycodon/norm/contin, methadone, MS Contin
4th:
Conversion of hydromorphone?
Challenge of using hydromorphone?
50 morphine is 10 of hydromorphone
Challenge is initiating ppl on it
Methadone features and MOA:
Full agonist at Mu receptors Lasts 5-150 hours based on genetics Prevent withdrawals/cravings from opiate abuse NMDA receptor blocker Can be used in neuropathic pain
Targin is:
What is Max Dose?
Probs?
Oxycodone + naloxone
40/20 bd
Probs: cancer, cirrhosis, liver needs to be good
Pethidine probs?
poor Promotes convulsions
Good anxiolytics
Very addictive
Codeine probs?
Attached to paracetomol so can OD on paracetomol
Reliant on CYP 2D6 conversion to morphine.
Erratic due to racial groups.
Constipates you.
VERY addictive.
Side effects of opiates
N/V - 40% (can be given metaclopramide)
Constipation (must give with Aperients - titrate)
Respiratory depression
Pruritus
Less saliva: poor dentition due to methadone syrup
Tolerance
Cerebral dysfunction, myoclonus: toxicity sign
Immune suppression
?bone metastasis (in vitro)
Bone density
Hypothyroid, gonadal, Hypothalamus-Pituitary-adrenal Axis.
Opioid induced hyperalgesia (see it within hours)
What is toxicity sign of opioids?
Myoclonus
Cerebral dysfunction: hallucination
Longer and more you’re on, more likely to get what side effect of opioid?
Opioid induced hyperalgesia
what is Analgesic adjuvants? Eg.?
Provides analgesia even though it’s primary purpose isn’t analgesia
Eg. Antidepressants: TCA, Clonidine NMDA - ketamine Anticonvulsants: Topiramate (migraine), (carbamazepine - trigeminal neuralgia) Steroids
Clonidine is?
A2 adrenergic agonist
Increased descending signal from brain to decrease pain
Ketamine SFx?
Hallucinations (Happy in kids, frightening in adults)
Gait
Topiramate used for
Migraine
Carbamazepine adjuvant for what?
Trigeminal
Steroids as adjuvants affects how?
Mainly dexamethasone
Euphorics
Appetite
Decreased oedema
When especially specifically use steroids for pain?
Brain tumour (raised ICP) Spinal cord compression
How much of bone must be missing to show up on X-ray for eg. metastasis?
40%
What investigations if think metastasis of vertebra?
CT
Bone scan
NSAIDS SFX
Fluid retaining (CCF)
Pro-thrombotic
Kidney
Gastritis: Diarrhoea, mouth ulcers
What dose to start someone on opioids?
10mg OxyContin BD, titrate as needed
Cancer analgesics
Treat or shrink the tumour. Radio, immuno, chemo, surgical Psycho Rehab SNAP Complimentary/alternatives EnvironMent Acupuncture
Immediate pain management for someone who’s really in distress
PCA (maybe)
Fentanyl (but REALLY short acting)
5mg SC or IV morphine, oxycodone, give another 5 if needed but depends on patient
