NSAIDs And opiates Flashcards
NSAIDs- analgesia?
Inhibits PGE2 formation- PGE2 increases fibre sensitivity to bradykinin, increases C fibre activity, increases nociception!
NSAIDs- anti inflammatory?
Inhibits prostaglandins production- reduces vasodilation (prostaglandins are potent vasodilators!)
NSAIDs- anti pyrexic?
IL-1 causes COX to make prostaglandins in hypothalamus- fever!! NSAIDs inhibit COX
Aspirin- anti platelet?
Irreversibly inactivated COX-1, stops platelets making thromboxane! Decreasing platelet aggregation!
NSAIDs- PKs?
90-99% protein bound!!!
Aspirin- zero order kinetics at high doses!!
NSAIDs- ADRs?
Gastric ulcers/haemorrhage (give PPI), water retention and hypertension, Stevens-Johnson, rash, bronchospasm
NSAIDs renal effect?
Prostaglandins normally maintain renal blood flow, decreased prostaglandins decreases blood flow, decrease GFR!
NSAIDs - general mechanism?
Inhibit COX-1 (always produced, ADRs) and COX-2 (produced in inflammation, therapeutic effects!) inhibiting the production of prostaglandins!
NSAIDs- DDIs?
Plasma protein displacement!! Increases effects of other drugs !
- sulphonylureas -> hypoglycaemia
- warfarin -> bleeding
- methotrexate -> myelosuppression and other ADRs
NSAID uses?
Joint disorders, mild-moderate pain
Opiates- mechanism?
Agonists of opioid receptors -> decrease cAMP, decrease Ca2+ entry -> decreased neurotransmitter vesicles release -> stops propagation of pain signal!
Morphine…
Gold standard of pain relief, full opioid agonist
Methadone…
Very good oral bioavailability, long (24hrs) half life- good for heroin withdrawal!
Codeine…
Prodrug, activated by CYP enzyme, polymorphisms decrease effect in some people!
Opiate ADRs?
Respiratory depression, confusion, psychosis, nausea,
Hepatic or renal problem-> increase ADR risk!!
