Exam 4 - Fibrinolytic Drugs

Question 1

all thrombolytics work to increase the conversion of _______ to _______

Answer 1

plasminogen to plasmin

Question 2

plasmin degrades _____

Answer 2

fibrin

(this dissolves a clot)

Question 3

_______ is an anticoagulant protein that circulates in inactive form and is deposited onto a growing clot

Answer 3

plasminogen

Question 4

_____ binds to fibrin and activates bound plasminogen to plasmin

Answer 4

t-PA (tissue plasminogen activator)

Question 5

_____ is a proteolytic enzyme that digests fibrin and fibrinogen

Answer 5

plasmin

Question 6

t-PA (tissue plasminogen activator) cleaves which bond to activate plasmin?

a. ser-pro
b. arg-val
c. pro-val
d. ser-arg

Answer 6

b. arg-val

Question 7

plasmin is inactivated by __________

Answer 7

alpha 2-antiplasmin

Question 8

t-PA (tissue plasminogen activator) is inhibited by ___ and ___

Answer 8

PAI-1 and PAI-2

(plasminogen activator inhibitor-1 and 2)

Question 9

3 indications for thrombolytic therapy

Answer 9

-acute MI
-acute ischemic thrombotic stroke
-pulmonary embolism (PE)

Question 10

when to initiate thrombolytic therapy for acute MI?

Answer 10

ASAP after onset of MI

Question 11

when to initiate thrombolytic therapy for acute ischemic thrombotic stroke?

Answer 11

only within 3 hours after onset and exclusion of intracranial hemorrhage

Question 12

what is the standard of care for acute MI?

Answer 12

stent placement

Question 13

how do drug-coated stents prevent restenosis?

Answer 13

drugs inhibit smooth muscle cell proliferation

(this inc risk of subsequent thrombosis)

Question 14

which t-PA thrombolytic drug lacks the fibrin binding domain, making it less fibrin-specific?

a. alteplase (Activase)
b. reteplase (Retevase)
c. Tenecteplase (TNKase)

Answer 14

b. reteplase (Retevase)

Question 15

which thrombolytic drug is recombinant human t-PA with 527 AA residues and binds fibrin?

a. alteplase (Activase)
b. reteplase (Retevase)
c. tenecteplase (TNKase)

Answer 15

a. alteplase (Activase)

Question 16

which thrombolytic drug is recombinant human t-PA with deletion of AA 355/527?

a. alteplase (Activase)
b. reteplase (Retevase)
c. tenecteplase (TNKase)

Answer 16

b. reteplase (Retevase)

Question 17

which thrombolytic drug is a recombinant, mutant form of t-PA, is given by single IV bolus, and is more fibrin specific than t-PA?

a. alteplase (Activase)
b. reteplase (Retevase)
c. tenecteplase (TNKase)

Answer 17

c. tenecteplase (TNKase)

Question 18

mutations in the tenecteplase structure _____ half life, _____ inhibition by PAI, and _____ activity at thrombi

Answer 18

inc; reduce; enhance

Question 19

which has the longest half-life?

a. alteplase (Activase)
b. reteplase (Retevase)
c. tenecteplase (TNKase)

Answer 19

c. tenecteplase (TNKase)

Question 20

what is the most common complication of t-PA thrombolytics?

Answer 20

bleeding

Question 21

how are t-PA thrombolytic drugs administered?

Answer 21

IV only

Question 22

anti-fibrinolytics are used to stop _____ caused by thrombolytic drugs

Answer 22

bleeding

Question 23

anti-fibrinolytic drugs such as aminocaproic acid (EACA) or tranexamic acid act as a _____ analog to bind the receptor on plasminogen and plasmin

a. pro
b. ser
c. val
d. lys

Answer 23

d. lys

(plasmin binds to fibrin through a lysine binding site to activate fibrinolysis, so these drugs can block plasmin binding to target fibrin)

Question 24

which is more potent?

a. aminocaproic acid (EACA)
b. tranexamic acid

Answer 24

b. tranexamic acid

(10x more potent)

Question 25

which is NOT a clinical use of anti-fibrinolytic agents?

a. adjunct therapy in hemophilia
b. re-bleeding from intracranial aneurysms
c. acute MI
d. bleeding associated with thrombolytic therapy

Answer 25

c. acute MI

Question 26

what is the main risk of anti-fibrinolytic agents?

Answer 26

thrombosis

Question 27

tranexamic acid and aminocaproic acid prevent binding of plasminogen and plasmin to _____, sparing clots and preventing hemorrhage

Answer 27

fibrin