Arterial Thrombosis and Anti-platelet drugs

Question 1

arterial thrombotic events

Answer 1

coronary, cerebral, peripheral

Question 2

arterial thrombosis treatment

Answer 2

• aspirin and other anti-platelet drugs
• modify risk factors for atherosclerosis (smoking, BP, diabetes)

Question 3

atherosclerosis- what happens/pathophysiology

Answer 3

damage to endothelium

‘foamy’ macrophages rich in cholesterol are recruited to the damage

forms plaques rich in cholesterol

Question 4

stable atherosclerotic plaques

Answer 4

Hyalinised and calcified

Stable plaques: stable angina (coronary artery), intermittent claudication (leg artery)

Question 5

unstable atherosclerotic plaques

Answer 5

Plaques rupture, platelets are recruited and cause acute thrombosis

Sudden onset of symptoms

Unstable angina or myocardial infarction (coronary arteries)

Stroke (cerebral arteries)

Question 6

Unstable atherosclerotic plaques - gradual or sudden onset of symptoms?

Answer 6

sudden

Question 7

are plaque ruptures more likely in veins or arteries

Answer 7

Plaque ruptures – more likely in the high pressure environment of arteries

Question 8

Factors that cause damage to endothelium, increase in foamy macrophages and platelet activation:

Answer 8

Factors that cause damage to endothelium, increase in foamy macrophages and platelet activation:
- Hypertension (damage to endothelium,
platelet activation)

- Smoking (endothelium, platelets)

- High cholesterol (accumulated in plaque)

- Diabetes mellitus (endothelium, platelets, 
  cholesterol)

Question 9

prevention of arterial thrombosis

Answer 9

Stop smoking
Treat hypertension
Treat diabetes
Lower cholesterol
Anti-platelet drugs

Question 10

platelets are formed in the ____ _____ by ‘budding’ from ___________

Answer 10

bone marrow
megakaryocytes

Question 11

what is the mean lifespan of platelets

Answer 11

7-10 days

Question 12

what do platelets releasee to further stimulate platelet activation in order to recruit more platelets

Answer 12

Thrombin,Thromboxane A2 and ADP

Question 13

Aspirin inhibits __________ which is necessary to produce Thromboxane A2 (a platelet agonist released from granules on activation).

Answer 13

cyclo-oxygenase

Question 14

Aspirin inhibits cyclo-oxygenase which is necessary to produce ____________ (a platelet agonist released from granules on activation).

Answer 14

Thromboxane A2

Question 15

side effects of aspirin

Answer 15

1. Bleeding
2. Blocks production of prostaglandins:
   
   • GI ulceration
   • Bronchospasm

Question 16

how does clopidogrel work

Answer 16

blocks ADP receptor

Question 17

Dipyridamole mechanism of action

Answer 17

Phosphodiesterase inhibitor - increases production of cAMP which inhibits platelet aggregation.

Question 18

GP IIb/IIIa inhibitors example

Answer 18

abciximab

Question 19

GP IIb/IIIa inhibitors mechanism of action

Answer 19

inhibit aggregation

Question 20

Platelets attach to each other via ________ and _________.

Answer 20

GPIIbIIIa
fibrinogen

Question 21

How long before elective operations should anti-platelet agents be stopped

Answer 21

7 days

Question 22

If serious bleeding, how could we potentially reverse

Answer 22

platelet transfusion

Question 23

arterial thrombosis conclusions

Answer 23

Causes organ ischaemia and is an inflammatory disorder instigated by damage to the endothelium

Platelets are central and are recruited to ruptured plaques

Antiplatelet drugs are useful in prevention

Question 24

venous thrombosis conclusions

Answer 24

Occurs in a low pressure system mainly by stasis

Platelets are not largely involved, and clots are rich in fibrin

Anticoagulants are useful in prevention