Thrombolytics

Question 1

How do the anticoagulants differ from the thrombolytic/fibrinolytic drugs?

Answer 1

Anticoagulants are prophylactic / used to prevent clot propagation, but do not lyse already formed clots; thrombolytics do lyse already formed clots

Question 2

Thrombin is the most important molecule in the initiation of clot formation; what is the most important molecule in the initiation of thrombolysis/fibrinolysis?

Answer 2

Plasminogen/Plasmin

Question 3

Name the 4 fibrinolytic drugs.

Answer 3

Streptokinase, urokinase, reteplase, tenectaplase

Question 4

Which 2 of the fibrinolytic drugs are nonspecific, meaning that they convert circulating plasminogen to plasmin throughout the body, and not just at the clot?

Answer 4

Streptokinase and urokinase

Question 5

Which 2 of the fibrinolytic drugs are genetically engineered from t-PA (tissue plasminogen factor) and specifically activate fibrin-bound plasminogen?

Answer 5

Reteplase and tenecteplase

Question 6

Name 4 conditions that fibrinolytics are used to treat.

Answer 6

Acute MI, acute stroke, central DVT, and multiple PE

Question 7

List the 6 antiplatelet drugs.

Answer 7

Acetylsalicylic acid, dipyridamole, clopidogrel, abcximab, eptifibatide, tirofiban

Question 8

Which 3 of the antiplatelets are GPIIb/IIIa antagonists, meaning that they block the platelet receptor for fibrinogen?

Answer 8

Abciximab, eptifibatide, tirofiban

Question 9

Which of the antiplatelets irreversibly inhibits platelets by preventing thromboxane A2 formation?

Answer 9

Acetylsalicylic acid

Question 10

“Baby aspirin” is often given to prevent what 2 conditions?

Answer 10

MI and stroke

Question 11

What enzyme does the antiplatelet dipyridamole inhibit, what molecule increases in concentration, and what happens to platelets as a result?

Answer 11

PDE (phosphodiesterase); cAMP; platelet aggregation weakly decreases

Question 12

To what receptor does clopidogrel bind in order to reduce platelet aggregation?

Answer 12

The platelet ADP receptor

Question 13

Which antiplatelet drug is a monoclonal antibody directed specifically against GPIIb/IIIa, and why is its repeated use limited?

Answer 13

Abciximab; may cause an immune response

Question 14

Which 2 antiplatelets are fibrinogen analogs that compete with endogenous fibrinogen and vWF for the IIb/IIIa receptors?

Answer 14

Eptifibatide and tirofiban

Question 15

Which antiplatelet causes a dose dependent antithrombotic effect that inhibits 80% of platelets within 5 hours, remains present for up to 10 days, and can be reversed by platelet transfusion?

Answer 15

Clopidogrel

Question 16

Which antiplatelet can occasionally cause TTP as a side effect?

Answer 16

Clopidogrel

Question 17

Name 4 antiplatelet drugs that are given parenterally.

Answer 17

Dipyridamole, abciximab, eptifibatide, tirofiban