Pharmacology of VTE

Question 1

Unfractionated Heparin UFH

Answer 1

Prevent and treat thrombosis

Sulfa drug

Question 2

Unfractionated Heparin UFH MOA

Answer 2

Binds to antithrombin increasing the activity of antithrombin (no platelet activation) –> inhibit IIa and Xa
MINIMUM LENGTH OF SACCHARID CHAIN IS 18 UNITS
But will binds and inactivates X if <18
Cause release of TFPI (enhances X inhibition)

Question 3

Unfractionated Heparin UFH ADME and PK

Answer 3

IV only (30-70% bio)
Renal and hepatic dose adjust

Question 4

Unfractionated Heparin UFH AE

Answer 4

Osteoporosis
Bleeding
Aldosterone synthesis inhibition
Thrombocytopenia (HAT and HIT)

Question 5

Low Molecular Weight Heparin

Answer 5

Tinzaprin 6.5
Dalteparin 6
Enoxaparin 4.5
Okay in prego

Question 6

Low Molecular Weight Heparin MOA

Answer 6

Prevents the growth and propagation of thrombi
Enhances/accelerates activity of antithrombin –> inhibit Xa and II
Release of TFPI

Question 7

LMWH Special properties

Answer 7

Limited anti-thrombin activity

Greater anti-factor Xa activity

Question 8

LMWH advantages over UFH

Answer 8

More predictable response
Dose-independent clearance
Longer half-life
Lower HIT

Question 9

Fondaparinux

Answer 9

Binds to antithrombin –> permanent conformation change –> inactivate X
No direct thrombin effect, controls some fibrin generation
Not in renal insuff

Question 10

Fondaparinux special properties

Answer 10

Anticoagulation effects last 2-4 days after discontinuation of the drug

Question 11

Idraparinux

Answer 11

Version of Fondaparinux
Longer half life
No antagonist available

Question 12

Direct Anti-Factor Xa Inhibitors

Answer 12

Rivaroxaben
Apixabin
Do not requier antithrombin
NO ANTIDOTE
Cyp interaction

Question 13

Direct Thrombin Inhibitors Advantages over others

Answer 13

Don’t require antithrombin
Inhibit circulating and clot-bound thrombin!!!!!!!
Do not induce immune mediated penia
Treat HIT

Question 14

DTI Drugs

Answer 14

Lepirudin
Desirudin
Bivalirudin
Argatroban
Dabigatran (PO)

Question 15

DTI MOA

Answer 15

Block II so no fibrinogen to fibrin

Question 16

Lepirudin (Refludan)

Answer 16

DTI
Binds tightly to fibrin/fibrinogen binding site
HIT/VTE
Possible bleeding and watch renal insuff

Question 17

Desirudin (Iprivask)

Answer 17

DTI
Prophylaxis of DVT
Irreversible bond and renal excretion (possible bleeding and renal insuff)

Question 18

Balvalirudin (Angiomax)

Answer 18

DTI
Unstable angina
Reversible bond –> antithrombotic activity
Hepatic excretion!!!!

Question 19

Argatroban

Answer 19

DTI
Reversible bond to catalytic site of thrombin on soluble and clot bound
Hepatic ONLY!!!

Question 20

Dabigatran (Pradaxa)

Answer 20

DTI
ORAL
Reversible bond to catalytic site of thrombin
Renal!
Prophylaxis

Question 21

DTI AE

Answer 21

Bleeding

Renal/Liver dysfuction prolongation of drug