Thrombolytic Drugs

Question 1

How do tissue plasminogen activators work?

Answer 1

Cleave Arg-Val bond to activate Plasmin

Question 2

Plasmin is turned off by

Answer 2

alpha2-antiplasmin

Question 3

tPA is inhibited by…

Answer 3

PAI-1 and PAI-2

Question 4

Difference in how streptokinase and recombinant tPA work

Answer 4

Strep - Forms activator complex with plasminogen

tPA – Catalyzes conversion of plasminogen to plasmin

Question 5

Indications for thrombolytic therapy

Answer 5

MI asap
Ischemic thrombotic stroke (w/in 3 hrs, exclude hemorr.)
PE

Question 6

Three major forms to tPA

Answer 6

Alteplase
Reteplase
Tenecteplase

Question 7

Important differences in Reteplase and Tenecteplase from Alteplase

Answer 7

Tenec – Recombinant, longer 1/2 life, more fibrin specific

Rete – More potent, but loss of binding domain -> less specific

Question 8

Difference in where tPAs work?

Answer 8

Alt and Tenec – cleave plasminogen that is already bound to fibrin
Rete – hits plasmin and plasminogen everywhere

Question 9

Important details about tPAs

Answer 9

IV admin
1/ life of 5/10 mintues
Can cause bleeding probs

Question 10

How do anti-fibrinolytic agents work

Answer 10

Act as a lysine analog to bind the receptor on plasminogen and plasmin to blockade plasmin binding to fibrin

Question 11

Clinical used of anti-fibrinolytic agents

Answer 11

Treat bleeding associated with thrombolytic therapy
Adjunct therapy in hemophilia
Re-bleeding from intracranial aneurysms

Question 12

Major risks of anti-fibrinolytic agents

Answer 12

Intravascular thrombosis as result of fibrinolysis inhibition
Thrombi formed during therapy are not easily lysed

Question 13

Name the two main anti-fibrinolytic agents

Answer 13

Aminocaproic Acid

Tranexamic acid