Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medicine Year 1 - Semester 2 - Part 2 > NSAIDS > Flashcards

NSAIDS Flashcards

1
Q

State the main actions of NSAIDs

A
  1. Anti-inflammatory
  2. Analgesic
  3. Anti-pyretic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Primary action of NSAIDs

A

Inhibit prostaglandin biosynthesis by direct action on cyclo-oxygenase enzymes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the mechanism of action of NSAIDs

2 main mechanisms of action

A

All inhibit cycle-oxygenase (COX) by 2 main mechanisms :

  1. An irreversible, time-dependent inhibition of the enzyme
  2. A rapid, reversible competitive inhibition of the enzyme
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Example of irreversible, time-dependent inhibition of the enzyme

A

Aspirin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the action of aspirin

A

Inactivates the enzyme

Aspirin acetylates the alpha-amino group of the terminal serine of the enzyme forming a covalent bond.

Further synthesis of prostaglandins requires synthesis of new enzyme.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Example of a rapid, reversible, competitive inhibition of the enzyme

A

Ibuprofen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the method of action of ibuprofen

A

Binds reversibly to the enzyme

Competes with natural substrate - arachidonic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe prostaglandins

A

Family of compounds - PGE2 and PGF2a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How are prostaglandins formed ?

A

Generated in tissues from a precursor (arachidonic acid) by cycle-oxygenase enzymes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

State the 2 main cyclo-oxygenase enzymes

A

COX-1
COX-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

State the products of arachidonic acid metabolism

A

Thromboxanes
Prostaglandins
Leukotrienes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe COX-1

A

Constitutive (always present)

Important in maintaining GIT (gastro-intestinal) integrity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe COX-2

A

Inducible

Involved in inflammatory response

Implicated in cancer development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Role of prostaglandins in inflammation

A

Inflammation is always accompanied by the release of prostaglandins.

  • Predominantly PGE2 and PGI2
  • PGD2 from mast cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Function of PGE2, PGI2 and PGD2

A

Acts as potent vasodilators

Also synergise with other inflammatory mediators

Potentiate histamine and bradykinin actions on post capillary venue permeability and pain sensory nerves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Key function of prostaglandins

A

Mediators of inflammation

  • particularly vasodilation and resultant oedema
  • less effect on cellular accumulation or migration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Inflammatory mediators

A

Histamine
Bradykinin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the anti-pyretic effects of NSAIDs

A

NSAIDs act by preventing the formation of prostaglandins and prevent the rise in temperature.
- no effect on normal body temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe prostaglandins role in body temperature

A

Body temp regulated by hypothalamus

  • fever occurs when hypothalamic thermostat is raised
  • bacterial endotoxins cause release of factors from macrophages
  • Interleukin 1 causes generation of prostaglandins in hypothalamus
  • Prostaglandins increase the thermostat set point
19
Q

Describe the analgesic effect of NSAIDs

A

By preventing prostaglandin production, NSAIDs prevent sensation to pain-producing compounds.

20
Q

Describe prostaglandins role in pain production

A

Inflamed regions painful due to histamine and bradykinin release

  • activate nociceptive afferent nerve terminals
  • register a painful stimulus

Prostaglandins sensitise nociceptive nerves to these compounds

21
Q

State some NSAID drugs

A

Salicylates - aspirin family

Propionic acids and fenamates

Paracetamol - acetaminophen

Coxibs

22
Q

Mechanism of action of salicylates - aspirin

A

Pro-drug (acetylsalicylic acid) can directly acetylate COX enzyme

Also metabolised to active compound (salicylic acid) by plasma and tissue esterase.

23
Q

Duration of action of aspirin

A

Salicylates found in plasma within 30 minutes.

Peak plasma concentrations within 1-2 hours

24
Side effects on the stomach of salicylates
Bleeding, Ulcers
25
Systemic side effects of salicylates
Tinnitus Dizziness Impaired Hearing Nausea Vomiting Hypersensitivity
26
Metabolic changes - side effects of salicylates
Acid/Base balance affected
27
Haemostatic side effects of salicylates
Blood coagulation affected through and action on platelets
28
CNS side effects of salicylates
Stimulation initially, ultimately coma and respiratory depression
29
Renal side effects of salicylates
Insufficiency in susceptible patients and with chronic use and overdose
30
Describe some features of propionic acids
- not prodrugs - Well absorbed - Lasts for 4-6 hours
31
Give an example of propionic acids
Ibuprofen, Naproxen
32
Give an example of a fenamate
Mefenamic acid
33
State some features of paracetamol
- Good analgesic and anti-pyretic activity - Poor anti-inflammatory - Well tolerated in GI tract - Weak COX inhibitor
34
Feature of paracetamol - COX related feature
Weak COX inhibitor - May be selective inhibitor of CNS-specific COX, COX-3
35
Describe the duration of action of paracetamol
Given orally - Peak plasma concentration 30-60 mins - t1/2 in plasma 2-4 hours for therapeutic doses
36
Comparison between paracetamol and other NSAIDs
Paracetamol has fewer side effects than other NSAIDs Due to selectivity for COX enzymes
37
Issue with paracetamol
Hepatotoxicity due to overdose - Normally inactivated in the liver by glucoronate and sulphate conjugation - When these enzymes saturated, toxic metabolites are formed - Result can be hepatic necrosis
38
Selective COX-2 inhibitors
Coxibs e.g. Celecoxib
39
What are selective COX-2 inhibitors used for ?
Used for osteoarthritis and rheumatoid arthritis
40
When are selective COX-2 inhibitors used ?
Restricted for when traditional NSAIDs produce too severe GI tract side effects Cardiovascular risk needs to be assessed
41
Uses of NSAIDs for analgesia
Headache Backache Bony metastases of cancer Postoperative pain Dysmennorhea
42
Clinical uses of NSAIDs
Analgesia Anti-inflammatory actions Anti-pyretic actions
43
Short-term analgesia
Aspirin Paracetamol Ibuprofen
44
Longer-lasting drugs for chronic pain
Naproxen Diclofenac
45
Uses of NSAIDs for anti-inflammatory actions
Both chronic or acute inflammatory actions Dosage for chronic inflammatory disorders is high Coxibs sometimes used for osteoarthritis and rheumatoid arthritis
46
Uses of NSAIDs as an anti-pyretic
To lower temperature Paracetamol is preferred, as it lacks GI tract side effects

Medicine Year 1 - Semester 2 - Part 2 (53 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions