anti clotting drugs

Question 1

Name the type of anti clotting drugs

Answer 1

1. antiplatelets
2. anti coagulants
3. anti thrombin

Question 2

Name the classes of antiplatelet drug

Answer 2

1. NSAID : aspirin
2. platelet GPIIa/b receptors blocker
3. ADP blocker
4. PDE inhibitor

Question 3

Aspirin MOA

Answer 3

inhibit cyclooxygenase, inhibit conversion of arachidonic acid into prostaglandin

Question 4

Aspirin clinical uses

Answer 4

1. prophylaxis for cerebral ischemia
2. prevent recurrent myocardial infarction

Question 5

Aspirin adverse effects

Answer 5

1. GI bleeding and ulcers
2. bruising and bleeding

Question 6

What are GPIIa/b receptors

Answer 6

• platelet membrane surface proteins
• mainly for fibrinogen
• activation of receptor complex is the final common pathway of platelet aggregation

Question 7

Name 3 platelet GPIIa/b receptor blockers

Answer 7

ATE
1. Abciximab : humanised monoclonal ab
2. Tirofiban: small molecule blocker
3. Eptifibatide

Question 8

Platelet GPIIa/b receptor blockers clinical uses

Answer 8

prevent restenosis
used for acute coronary syndrome

Question 9

Name 2 ADP receptor blockers

Answer 9

1. clopidogrel
2. ticlopidine

Question 10

ADP receptor blockers MOA

Answer 10

prevents ADP from binding to ADP receptor, prevent activation of platelets

Question 11

Name a PDE inhibitor

Answer 11

dipyridamole

Question 12

Dipyridamole MOA

Answer 12

• inhibits phosphodiesterase
• prevents breakdown of cAMP
• increase levels of cAMP in platelets
• decrease platelet aggregation and adhesion

Question 12

Name the anticoagulants

Answer 12

1. heparin
2. wafarin
3. anti thrombin III

Question 12

Heparin MOA

Answer 12

• heparin binds to ATIII, causing conformational change to ATIII active site, exposing it to the enzyme (thrombin factor IIa)
• heparin is also required to bind to the protease to inhibit thrombin
• inhibit conversion of fibrinogen to fibrin
• prevent clotting

Question 12

Heparin clinical uses

Answer 12

1. deep vein thrombosis
2. pulmonary embolism
3. actue myocardial infarction
   - can be used in pregnancy

Question 12

Heparin bioavailability

Answer 12

• given IV/ subcutaneous
  given IM during haematomas

Question 13

Heparin adverse effect

Answer 13

1. thrombocytopaenia
2. haemorrhage
   - stop heparin and use protamine sulfate (antidote for heparin)

Question 13

Warfarin MOA

Answer 13

• inhibit vitamin K reductase: convert vit K into its active form
  (vit K is essential for formation of clotting factors 2,9,10,12)
• reduce vit K available in liver
• decrease activation of clotting factors

Question 14

warfarin clinical uses

Answer 14

same as heparin
CANNOT BE USED IN PREGNANCY

Question 15

wafarin adverse effects

Answer 15

1. bleeding
2. cross placenta and cause haemorrhagic disorder in fetus
3. hep clearance by cytochrome P450 : DDI!!!!

Question 16

Name 4 thrombolytic agents

Answer 16

1. tissue plasminogen activator (alteplase)
2. urokinase
3. streptokinase
4. anistreplase

Question 17

thrombolytic agents MOA

Answer 17

• activate plasminogen into its active form plasmin
• plasmin cleaves fibrin which is the main component of the clot

Question 18

thrombolytic agents bioavailability

Answer 18

1. IV injection
2. intracoronary injection

Question 19

thrombolytic agent clinical uses

Answer 19

1. emergency treatement of coronary artery thrombosis
2. peripheral arterial thrombosis and emboli
3. ischaemic stroke (<4.5 h)

Question 20

thrombolytic agent adverse effects

Answer 20

1. bleeding
2. impaired wound healing
3. contraindicated in pregnancy