07.1 NSAIDs

Question 1

What are COX enzymes?

Answer 1

Enzymes that convert a membrane phospholipid substrate (arachidonic acid) into prostaglandins

Question 2

What is the difference between COX 1 and COX 2?

Answer 2

COX 1 - always expressed in the body

COX 2 - induced by cytokines in inflammatory cells

Question 3

Blocking which COX enzymes results in the most ADRs?

Answer 3

COX 1

Question 4

What are some examples of NSAIDs?

Answer 4

Ibuprofen, naproxen, diclofenac, celecoxib, aspirin

Question 5

What do NSAIDs do?

Answer 5

Block COX enzymes (COX 2 for therapeutic response) for analgesia, anti-inflammation and antipyresis

Question 6

What are some ADRs of NSAIDs?

Answer 6

Due to COX 1 inhibition
GI - ulcers and bleeding due to acid secretion, and a lack of blood flow and mucosal production
Renal - decrease in GFR and perfusion
Stephen-Johnson syndrome
Increased bleeding time

Question 7

Is paracetamol an NSAID?

Answer 7

No it is a NOAD

It is an analgesic and antipyretic

Question 8

What happens in paracetamol overdose?

Answer 8

Phase 2 saturates as glucoronide and sulphate are all conjugated
Phase 1 produces NAPQI which itself is toxic and saturates glutathione
NAPQI that is no conjugated is highly reactive and causes liver and kidney failure

Question 9

What is the treatment for paracetamol overdose?

Answer 9

0-4 hours = charcoal

0-36 hours = N-Acetyl Cysteine