NSAIDs( Pharmacology)

Question 1

What are NSAIDs?

Answer 1

Non-steroidal anti-inflammatory drugs

Question 2

What is inflammation?

Answer 2

The body’s response towards tissue injury that was caused by physical trauma, microbiological agents or noxious chemicals.

Question 3

What does inflammation assist the body with?

Answer 3

-Remove irritants
-Restore normal structure and function to damaged tissue.
-Inactivate and destroy the invading organisms.

Question 4

What is the rate limiting step for the formation of arachidonic acid?

Answer 4

Liberation of arachidonate which is catalyzed by phospholipid A2.

Question 5

What are the functions of prostaglandins?(4)

Answer 5

Formation of blood clots, inflammation, induction of labour and blood flow.

Question 6

Two major pathways for the synthesis of prostaglandins?(2)

Answer 6

Cyclooxygenase pathway
Lipoxygenase pathway

Question 7

Three steps of the biosynthesis of prostanoids

Answer 7

1. Mobilisation of AA from the membrane phospholipid through the action of phospholipase A2.
2. Bio-transformation of AA by cyclooxygenase through a bi-functional action which generates an unstable prostaglandin (PGG2) by cyclooxygenase reaction, and the immediate conversion to PGH2 using the same enzyme by a peroxidase reaction.
3. The conversion of PGH2 to specific prostanoids by the action of synthases and specific isomerases.

Question 8

Another name for cyclooxygenase

Answer 8

Prostaglandin-endoperoxidase synthase

Question 9

Physiological effects of COX-1 (4)

Answer 9

Maintenance of blood pressure.
Vascular homeostasis
Gastric protection
Platelets aggregation

Question 10

What induces the COX-2 enzyme?

Answer 10

Inflammatory stimuli

Question 11

What is the main function of COX-2?

Answer 11

Resp for the production of prostanoid mediators of inflammation.

Question 12

What role do NSAIDs do? (4)

Answer 12

Reduces pain, prevents fever, prevents blood clotting and decreases inflammation.

Question 13

Describe the mechanism of action of NSAIDs (3)

Answer 13

•NSAIDs are competitive inhibitors of the active site of COX enzymes (both of them), so they bind and inactivate the enzymes.
• By inactivating the enzymes they inhibit the formation of prastanoids prostaglandin, thromboxane and prostacyclin.
• Thereby preventing inflammation, platelet aggregation, and preventing the pain stimulus from reaching the brain ( no prostaglandins) and is not felt.

Question 14

Therapeutic effects of NSAIDs (3)

Answer 14

Anti-inflammatory, antipyretic and analgesic effects.

Question 15

Pharmacological uses of NSAIDs (6)

Answer 15

Headaches, menstrual pain, symptomatic relief, postoperative, chronic joint diseases, acute inflammatory injuries.

Question 16

Adverse effects of NSAIDs in:
A. GIT (7)
B. Kidneys (2)
C.Skin (1)
D. CNS (3)
E. Haematopoietic effects (3)

Answer 16

A. Abdominal pains, bleeding, anaemia, ulceration, nausea and vomiting , diarrhoea
B. Renal necrosis and haematuria.
C. Stevens johnson syndrome (very rare, fatal)
D. Depression, headache, vertigo
E. Leukopenia, thrombocytopenia, prolonged bleeding due to poor blood clotting.

Question 17

Examples of non-selective COX inhibitors

Answer 17

Ibuprofen, Aspirin, Neproxen

Question 18

How is paracetamol different from non-selective COX inhibitors?

Answer 18

Paracetamol only has anti-diuretic and analgesic effects, it has poor anti-inflammatory effects

Question 19

Examples of COX-1selective inhibitors (3)

Answer 19

Transact, toradol and strepsils

Question 20

Examples of COX-2 selective inhibitors

Answer 20

Meloxicam, celebrax and arcoxia

Question 21

Common adverse effects of both the selective inhibitors (3)

Answer 21

Dyspepsia
Diarrhoea
Abdominal pains

Question 22

An additional therapeutic effect of aspirin

Answer 22

Anti-platelet activity
-inhibits cox1 and prevents formation of thromboxane A2.
- no blood clotting.

Question 23

Aspirin can be used to prevent which type of cardiovascular disease

Answer 23

Strokes

Question 24

Which syndrome can be caused by aspirin (most common in children)?

Answer 24

Reye’s syndrome

Question 25

What are the effects of reye’s syndrome (2)

Answer 25

May result in liver and brain damage.

Question 26

Symptoms of Reye’s syndrome (5)

Answer 26

Rash, fever, vomiting, convulsions and death.

Question 27

Why is aspirin not used in pregnant or breastfeeding women

Answer 27

It is teratogenic, it can cross the placenta and it can be present in breastmilk.