Anticoagulant Drugs

Question 1

Which coagulation factors are Glycoproteins used to activated Serine proteases

Answer 1

8, 5, 3, S

Alto – Anti-thrombin III

Question 2

Hemophilia A is a deficiency of…

Answer 2

Factor 8

Question 3

Hemophilia B is a deficiancy of…

Answer 3

Factor 9

Question 4

What is Factor V Leiden

Answer 4

A mutation tat gives resistance to Protein C

Question 5

Where are clotting factors produced?

Answer 5

Liver (except VWF in the endothelial cells and megakaryocytes)

Question 6

Role of factor 13

Answer 6

Cross links fibrin into stable clots incorporated into platelet plug

Question 7

What are PT, aPTT, and Bleeding Time used to assess

Answer 7

PT – Monitor Oral Anticoagulation therapy
aPTT – Monitor heparin therapy
Bleeding Time – Abnormal with defect in platelet number or fxn

Question 8

INR =

Answer 8

(Patient PT/Control PT)^International sensitivity index

Question 9

How does Warfarin work?

Answer 9

Inhibit the reduction of Vitamin K, which is essential for factors 2, 7, 9, 10, C, and S

Question 10

Timeline on Warfarin efficacy

Answer 10

Will take 3-5 days to deplete the pool of circulating clotting factors. Takes several dys to re-synthesize factors after discontinuing therapy.

Question 11

Warfarin is matabolized by…

Answer 11

Cyp 2C9

Question 12

Important details about Warfarin Overdose…

Answer 12

Iatrogenic Hemorrhage

Discontinue Warfarin and Give Vitamin K or plasma

Question 13

Features of fetal warfarin syndrome

Answer 13

Nasal Hypoplasia

Abnormal Bone Formation

Question 14

Aside from reversing warfarin, when else might you dose someone with Vitmain K

Answer 14

Fat absorption anomalies

Newborns

Question 15

How does Heparin work

Answer 15

Binds and activates antithrombin III

Then dissociated and interacts with even more

Question 16

Antithrombin III can inactivate…

Answer 16

Thrombin

Factors 7, 9, and 10

Question 17

Main adverse effect of Heparin to watch for an impt. details

Answer 17

Iatrogenic Hemorrhage
RFs – Over 50, Ulcers, Severe HTN, Antiplatelet Drugs
Tx – Stop Hep, Specific antagonist if life threatening

Question 18

What is the Heparin’s antidote?

Answer 18

Protamine sulfate

Question 19

The other two important adverse effects of Heparin use to watch for

Answer 19

Thrombocytopenia (7-12 days post therapy, Ab against PF4-Heparin compex)
Osteoporosis (After 3-6 months of treatment)

Question 20

Heparin’s _____ groups are required for antithrombin binding

Answer 20

Sulfate groups

Question 21

Perks of Low molecular weight heparin

Answer 21

Less frequent dosing, longer half life
No clotting monitoring needed
Less thrombocytopenia and osteo

Question 22

Main form of low moledular weight heparin

Answer 22

Danaparoid

also Enoxaparin, Tinzaparin

Question 23

How is the activity of LMW Heparin different from normal Hep

Answer 23

Binding to AT leads to preferential inhibition of Factor X, parely hits thrombin

Question 24

Important Factor Xa inhibitors

Answer 24

Fondaparinux Sodium
Rivaroxaban (Xarelto)
Apixaban (Eliquix)
Edoxaban

Question 25

Important details on Fondaparinux Sodium

Answer 25

Indirect inhib of Factor X by AT binding SC once daily used for DVT, Prophylaxis of surgical patient (abdominal and ortho surgery) NOT REVERSIBLE BY PROTAMINE SULFATE

Question 26

What is Rivaroxaban (Xarelto) used for?

Answer 26

Prevent VT, PE, and thrombus in Afib

Question 27

What s Apixaban used for?

Answer 27

Prevent thrombus in A Fib

Question 28

Problem with discontinuing Factor Xa inhibitors?

Answer 28

Increased risk of stroke

Question 29

Important Edoxaban details

Answer 29

Treatment of VT and PE after briding anticoag | Quickly renally excreted

Question 30

Four significant Direct thrombin Inhibitors

Answer 30

``` Hirudin Desirudin Bivalirudin Argatroban Dabigatran ```

Question 31

Important details about Hirudin

Answer 31

Peptide from leach saliva

Question 32

Important details about Desirudin

Answer 32

Recombinant Hirudin from yeast Irreversible inhibition of thrombin No effect on AT, aPTT values increase dose-dependently HS rxns

Question 33

Important details about Bivalirudin

Answer 33

Reversible binding, rapid onset and short duration Given via IV in PCA No Ab formation

Question 34

Important details about Argatroban

Answer 34

Reversible binding Monitor with aPTT Half life of 40-50 minutes Prophylaxis/Treatment in patients with Hep-induced thrombocytopenia