Hematological Agents I

Question 1

Antiplatelet therapies are useful for? Not so useful?

Answer 1

Useful for arterial thrombosis.

Not so much for venous thrombosis

Question 2

ASA MOA

Answer 2

Irreversibly blocks COX-1 in platelets which reduces TA2 which reduces platelet activation and aggregation

Question 3

Dipyridamole MOAs

Main goal

Answer 3

Main goal is decrease platelet activation and aggregation

1. Inhibits phosphodiesterase which increases cAMP which decreases calcium which decreases activation and aggregation
2. Inhibits adenosine reuptake into platelets which eventually causes increased cAMP and so on

Question 4

Which two drugs are prodrugs that irreversibly bind P2Y12 receptors?

Answer 4

Clopidogrel and prasugrel

Question 5

Tricagrelor and Cangrelor MOA

Answer 5

Not prodrugs
Reversible P2Y12 (ADP) receptor antagonists

Question 6

Two reasons why clopidogrel may not work well

Answer 6

1. Polymorphisms in CYP2C19 (the enzyme that activates clopidrogel)
2. Omeprazole inhibits CYP2C19

Question 7

Toxicity difference between Tricagrelor/Prasugrel and Clopidogrel?

Answer 7

Prasugrel and Ticagrelor have greater rates of fatal and life-threatening bleeding

Question 8

Abciximab
Eptifibatide
Tirofiban
MOAs
Which one has the highest risk of thrombocytopenia?

Answer 8

Abciximab- fragment monoclonal antibody inhibitor of GPIIb/IIIa. Highest risk of thrombocytopenia
Eptifibatide- peptide inhibitor of GPIIb/IIIa
Tiorfiban- nonpeptide small molecule that inhibits GPIIb/IIIa

Question 9

Indirect inhibitors of thrombin and/or Factor Xa? (3)

Answer 9

1. Heparin
2. Enoxaparin (LMWH)
3. Fonfaparinux (really small heparin)

Question 10

Direct thrombin inhibitors (4)

Parenteral or oral for each

Answer 10

1. Lepirudin- parenteral
2. Bivalirudin- parenteral
3. Argatroban- parenteral
4. Dabigatran- oral

Question 11

Direct Factor Xa inhibitors (2)

Answer 11

Rivaroxaban (oral)

Apixaban (oral)

Question 12

Vorapaxar MOA

Adverse effect

Answer 12

1. Protease activated receptor (PAR) antagonist that inhibits ability of thrombin to activate platelets
2. Can cause severe intra-cranial bleeding