Analgesia

Question 1

NSAIDs
- types
- moa
- SE 
- monitor
Why cox

Answer 1

Types

• non selective (ibuprofen)
• selective (cox 2) - celecoxib, parecoxib

Moa-
- analgesics, antipyretic, anti-inflammatory, reversible inhibit synthesis of prostaglandin by inhibit cox

Cox1- impair gastric cytoprotection, anti platelet effect

Cox2 - anti inflam and analgesic

SE
- increase risk of mi, stroke, CVA, HF and ht worsen due to renal impairment, reduction GFR, GI bleed, nausea, GERD, brochospasm, papillary necrosis, interstitial nephritis

CI in active bleed, GI bleed, hepatic impairment

Monitor: GIT bleed, UEC, LFT

Cox 2 better GIT but incrase risk of CVD

Question 2

Opioids
- type
- moa
- SE
- how to titirate 
Give what in conjunction 
Reverse with?

Answer 2

Types
- weak opioids: codeine, tramadol, pentazocine (partial agonist), Pethidine

• strong opioids: morphine, hydromorphine, oxycodone, fentanyl, methadone

Moa

• mimic endogenous opioids by activating opioid receptors (mu, kappa, delta) and act on GABA in central and peripheral nervous system -> resp depression! analgesia, sedation , constipating
• reduce transmission of pain by modulating descending inhibitory pathways from brain

SE-
Renal impairment can accumulate as all renal excrete except (fentanyl Nd oxycodone)
- n and v, constipation, resp depress, sedative, urinary retention, hypotension, resp depress, sphincter of oddi spasm, hepatotoxicity (avoid if impair)

Gives laxatives and antiemetic a

CI:
Comatose, resp compromise, renal impairment, hepatic impair

Reverse with naloxone (comp opioid recp anatsgonist)

Calculate:

• total dose + breakthrough
• retitrate and recalculate breakthroughs, give 1/6th daily dose, breakthrough 4 hr if needed

Question 3

Pain ladder

Answer 3

Bottom : non opioid (paracetamol, NSAIDs) +/- adjuvant

Middle:

Highest:

Adjuvant:

Question 4

Paracetamol

• dose
• moa
• SE
• what to do if overdose

Answer 4

Moa

• inhibition of central prostaglandin synthesis
• antipyretic effect due to reduce prostaglandin in hypothalamus

SE

• hepatoxicity (toxic metsbolite due to napqi produced by cytochrome p450)
• overdose can lead to overwhelm ros and free radical

Overdose do LFT and give nac (n-acetylcysteine) massive LFT increase (AST and alt)

Safe in pregnancy

Dose

• 1g 6 hourly (IV or Po)
• max 4 g per day in adults