NSAIDs Flashcards
What are the 4 properties of aspirin?
Anti-platelet
Anti-inflammatory
Analgesic
Antipyretic
How does aspirin perform its analgesic properties?
It blocks prostaglandin production, reducing sensitisation of nociceptive fibers to stimulation by other inflammatory mediators by prostaglandin action
It crosses the BBB, providing additional analgesic actions in the CNS
How does aspirin perform its antipyretic properties?
It blocks prostaglandin E2 production via COX inhibition, which reduces or prevents fever
What are the AE of salicylate toxicity?
Central hyperventilation Respiratory alkalosis Fever, dehydration Metabolic acidosis Respiratory acidosis Hypoprothrombinemia Vasomotor collapse Coma Renal and respiratory failure
Can children take aspirin?
No, due to development of Reye’s syndrome, which can cause brain and liver swelling, vomitting, personality changes, delirium and convulsions
How does the use of NSAIDs affect GIT?
Prostaglandins decrease gastric acid secretions, increases mucosal blood flow, increases mucus secretion and bicarbonate secretion. Prostaglandin production inhibition would prevent these, causing dyspepsia, nausea, vomitting, and ulcer formation, which possesses potential haemorrhage risk in chronic users
Effects of PGE2 inhibition renally
- Na+ retention
- H2O retention as a result
- Peripheral edema as a result
- Hypertension
Effects of PGI2 inhibition renally
- Suppression of renin and aldosterone secretion, which decreases Na+ reabsorption and K+ efflux
- Hyperkalemia
- Acute renal failure
Other AEs of NSAIDs besides GIT and renal
- Asthma
- Pseudoallergy
- Bleeding
Why are NSAIDs contraindicated in 3rd trimester of pregnancy?
Premature closure of ductus arteriosus in late pregnancy which causes heart dysfunction and likely death
List the NSAIDs from selectively COX-1 to selectively COX-2
Ketoprofen Piroxicam Indometacin Aspirin Naproxen Ibuprofen Diclofenac Mefenamic acid Meloxicam Celecoxib Etoricoxib
Drugs more selective for COX-2 than COX-1 have increased risk of _________?
Thrombosis due to relative increase in thromboxanes favouring platelet aggregation
Are COX-1 or COX-2 selective NSAIDs more prone to GI disturbance, renal dysfunctions and bleeding?
COX-1
Are COX-1 or COX-2 selective NSAIDs more prone to disruptions in wound healing?
COX-2
State the minor pathway of paracetamol metabolism, and why alcohol usage can cause toxicity
Paracetamol is metabolised by CYP450 2E1 into toxic metabolites, induced by alcohol.
In order to be converted into non-toxic metabolites, glutathione is required for this conversion. However, it is depleted by alcohol and paracetamol overdose.
