Pharmacology: Application - Haemostasis

Question 1

how do platelets adhere to VWF

Answer 1

via GPIb

Question 2

aggregation

Answer 2

platelets adhere to each other via GPIIbIIIa and fibrinogen

Question 3

what further stimulates platelet aggregation

Answer 3

granule release (i.e. thromboxane A2 and ADP)

Question 4

what stimulates further platelet activation

Answer 4

ADP receptors on platelet surfaces

Question 5

how do platelets expose more phospholipids on their surface and why

Answer 5

• by changing their shape

- to allow for increased surface area for coagulation activation and fibrinogen activation

Question 6

name 3 classes of anti-platelets

Answer 6

• ADP receptor antagonists
• thromboxane inhibitors
• alpha IIb beta3 inhibitors

Question 7

ADP receptor antagonists

Answer 7

• clopidogrel

- prasugrel

Question 8

thromboxane inhibitors

Answer 8

• aspirin

Question 9

alpha IIb beta3 inhibitors

Answer 9

• abciximab

- eptifibadine

Question 10

MoA of ADP receptor antagonists and thromboxane inhibitors

Answer 10

inhibits further platelet activation via ADP receptors/thromboxane A2

Question 11

treatment of arterial clot

Answer 11

• aspirin and other anti-platelets, atherosclerosis risk factor modification

Question 12

treatment of venous thrombus

Answer 12

• directed at fibrin clot formation/production - heparin/warfarin, thrombin inhibitors/Xa inhibitors

Question 13

what does warfarin target

Answer 13

• prothrombin

- factors VIIa, Xa, IXa

Question 14

what so serine protease inhibtors inhibit

Answer 14

inhibits

• thrombin
• factors: TF, VIIa, V, Xa, VIII, IXa

Question 15

what can an embolism from LA cause

Answer 15

stroke

Question 16

heparin MoA

Answer 16

• thrombin/factor Xa bind to anti-thrombin II which bind to heparin inactivating them
• therefore thrombin and fibrin formation can’t occur