Analgesics Flashcards
What are the mechanisms of action of paracetamol?
Inhibits COX => inhibits prostaglandin production
- anti-pyretic ( but can’t reach inflammation sites)
Inhibits anandamine (endocannabinoid) take up by neurones
Inhibits CNS Na+ channels => analgesia
What are the treatments for paracetamol OD?
Activated charcoal
N-acetylcysteine
Methionine
What is the name for IV paracetamol and what’s its use?
Perfalgan
- for short term post-operative use
What is the mode of action of NSAIDs?
Inhibit COX enxymes => inhibit prostaglandin production
- anti-inflammatory actioon => analgesic action
Describe the mode of action of opioids
Inhibits ascending pain pathways ia:
- direct inhbition of 1st order nociceptors
- indirect inhibition via activation of descending pathways
Give examples of weak opioids?
Codeine
Dihydrocodeine
Tramadol
What are the cautions with tramadol?
Lower seizure threshold
May induce CNS toxicity if on antidepressants
Give examples of strong opioids
Morphine, Fentanyl, Diamorphine, Hydromorphine, Methadone, Oxycodone, Pethidine, Buprenorphine, Remifentanyl
Which strong opioid is often used in renal impairment?
Fetanyl
Antidote for opioid overdose
Naloxone
- very short half life
What analgesia should be used to relief muscle spasm pain?
Antispasmodic
e.g. Baclofen (GABA-b receptor agonist )
Name an NMDA R-antagonist
Ketamine
Name anti-convulsants used as neuropathic analgesia
Gabapentin, Pregabalin, Carbamazepine
