Paracetamol
MoA:
1. COX inhibition preventing prostaglandin synthesis
2. Prevention of re-uptake of endocannabinoids
3. Enhancement of inhibitory serotonergic pathways
Side Effects: Generally well tolerated. Hepatotoxicity in overdose, hypotension with IV administration
NSAID's
Non-Selective (i.e. Ibuprofen)
MoA: Inhibition of COX 2 +/- COX 1 to decrease prostaglandin synthesis and hence, pain transmission
Side Effects: Renal dysfunction, GI ulceration/bleeding, and platelet dysfunction
COX-2 Selective (i.e. Celecoxib)
MoA: Selective inhibition of COX 2 to decrease prostaglandin synthesis and hence, pain transmission
Side Effects: Myocardial infarction, stroke, renal dysfunction
Opioids
MoA: Primarily μ GPCR agonistic activity but also has some weak κ and δ receptor activity
Side Effects:
CNS - Drowsiness, pinpoint pupils, tolerance and addiction
Resp - Respiratory depression, apnoea at high doses
GIT - Constipation, decreased bowel motility
Renal - Urinary retention
CVS - Mild Bradycardia and hypotension
Histamine release (hypotension, flushing, bronchospasm) in some opioids (morphine, endone)
Special Considerations:
Codeine - Variable efficacy between individuals
Oxycodone - Dose reduce/avoid in renal failure
Morphine - Dose reduce/avoid in renal failure
Hydromorphone - Careful with dosing - 10x more potent than morphine!