Coagulation Pharmacology

Question 1

Hemostasis

Answer 1

Arrest of bleeding from damaged blood vessel

Question 2

Coagulation

Answer 2

Multi step process to plug the leaking vessel

Question 3

platelets contain :

Answer 3

organelles, secretory granules

Question 4

platelets do not contain :

Answer 4

nucleus

Question 5

progression of microtubules of platelets

Answer 5

1. formation of centrosomal microtubule array
2. microtubules move to cortex
3. pseudopod formation
4. formation of protoplatelet elongation, and bending and branching to amplify ends
5. protoplatelet release

Question 6

extrinsic pathway initiating element

Answer 6

tissue factor

Question 7

intrinsic pathway initiating element

Answer 7

collagen

Question 8

platelet receptor for collagen

Answer 8

GP 1a

Question 9

platelet receptor for vWF

Answer 9

GP 1b

Question 10

release of ____from endothelial cells inhibit thrombogenesis

Answer 10

PGI2, prostacyclin

Question 11

Platelets secretions following activation

Answer 11

ADP
Thromboxane A2
Serotonin

Question 12

Function of platelet secretions

Answer 12

> 3 activate and recruit platelets

> TXA2/Serotonin are vasoconstrictors

Question 13

3 secret platelet secretions induce

Answer 13

> conformation of GPIIb/IIIa receptors to bind fibrinogen

Question 14

Function of fibrinogen

Answer 14

> cross-linking of platelets

> forms temporary hemostatic plug

Question 15

Function of fibrin

Answer 15

stabilizes and anchors aggregated platelets

Question 16

MOA of aspirin

Answer 16

> inhibits platelet COX-1 by acetylation
intereferes with platelet aggregation
prolongs bleeding time
prevents arterial thrombi formation

Question 17

Key action of aspirin

Answer 17

Inhibition of TXA2 synthesis

Question 18

Max effective aspirin dose

Answer 18

50-325mg/day

Question 19

higher doses of aspirin side effect

Answer 19

> blocks PGI2 synthesis

> risks of MI and clotting

Question 20

Therapeutic reasons for aspirin

Answer 20

> prevent coronary thrombosis in unstable angina
adjunct to thombolytic therapy
reducing recurrence of thrombotic stroke

Question 21

Clinical consequences of aspirin

Answer 21

> prolongs bleeding time, but no increase in PT time

> hemostasis returns to normal after 36hr after last dose

Question 22

Two types of ADP receptors

Answer 22

> Coupled to Gq - PLC - IP3 - Ca2+

> Coupled to Gi and inhibition of adenylyl cyclase

Question 23

Requirement of ADP activation of platelets

Answer 23

> both P2Y12 need to be activated for platelet activation by ADP

Question 24

Class of drugs that contain ADP activation of platelets

Answer 24

> thienopyridine class of ADP receptor inhibitors
> pro-drug

Question 25

Two drugs within the thienopyridine class

Answer 25

> ticlopidine

> clopidogrel

Question 26

Thienopyridine MOA

Answer 26

irreversibly block ADP receptor on platelet and subsequent activation of GPIIb/IIIa