Anticoagulant Drugs Flashcards
Which coagulation factors are Glycoproteins used to activated Serine proteases
8, 5, 3, S
Alto – Anti-thrombin III
Hemophilia A is a deficiency of…
Factor 8
Hemophilia B is a deficiancy of…
Factor 9
What is Factor V Leiden
A mutation tat gives resistance to Protein C
Where are clotting factors produced?
Liver (except VWF in the endothelial cells and megakaryocytes)
Role of factor 13
Cross links fibrin into stable clots incorporated into platelet plug
What are PT, aPTT, and Bleeding Time used to assess
PT – Monitor Oral Anticoagulation therapy
aPTT – Monitor heparin therapy
Bleeding Time – Abnormal with defect in platelet number or fxn
INR =
(Patient PT/Control PT)^International sensitivity index
How does Warfarin work?
Inhibit the reduction of Vitamin K, which is essential for factors 2, 7, 9, 10, C, and S
Timeline on Warfarin efficacy
Will take 3-5 days to deplete the pool of circulating clotting factors. Takes several dys to re-synthesize factors after discontinuing therapy.
Warfarin is matabolized by…
Cyp 2C9
Important details about Warfarin Overdose…
Iatrogenic Hemorrhage
Discontinue Warfarin and Give Vitamin K or plasma
Features of fetal warfarin syndrome
Nasal Hypoplasia
Abnormal Bone Formation
Aside from reversing warfarin, when else might you dose someone with Vitmain K
Fat absorption anomalies
Newborns
How does Heparin work
Binds and activates antithrombin III
Then dissociated and interacts with even more
Antithrombin III can inactivate…
Thrombin
Factors 7, 9, and 10
Main adverse effect of Heparin to watch for an impt. details
Iatrogenic Hemorrhage
RFs – Over 50, Ulcers, Severe HTN, Antiplatelet Drugs
Tx – Stop Hep, Specific antagonist if life threatening
What is the Heparin’s antidote?
Protamine sulfate
The other two important adverse effects of Heparin use to watch for
Thrombocytopenia (7-12 days post therapy, Ab against PF4-Heparin compex)
Osteoporosis (After 3-6 months of treatment)
Heparin’s _____ groups are required for antithrombin binding
Sulfate groups
Perks of Low molecular weight heparin
Less frequent dosing, longer half life
No clotting monitoring needed
Less thrombocytopenia and osteo
Main form of low moledular weight heparin
Danaparoid
also Enoxaparin, Tinzaparin
How is the activity of LMW Heparin different from normal Hep
Binding to AT leads to preferential inhibition of Factor X, parely hits thrombin
Important Factor Xa inhibitors
Fondaparinux Sodium
Rivaroxaban (Xarelto)
Apixaban (Eliquix)
Edoxaban
Important details on Fondaparinux Sodium
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
What is Rivaroxaban (Xarelto) used for?
Prevent VT, PE, and thrombus in Afib
What s Apixaban used for?
Prevent thrombus in A Fib
Problem with discontinuing Factor Xa inhibitors?
Increased risk of stroke
Important Edoxaban details
Treatment of VT and PE after briding anticoag
Quickly renally excreted
Four significant Direct thrombin Inhibitors
Hirudin Desirudin Bivalirudin Argatroban Dabigatran
Important details about Hirudin
Peptide from leach saliva
Important details about Desirudin
Recombinant Hirudin from yeast
Irreversible inhibition of thrombin
No effect on AT, aPTT values increase dose-dependently
HS rxns
Important details about Bivalirudin
Reversible binding, rapid onset and short duration
Given via IV in PCA
No Ab formation
Important details about Argatroban
Reversible binding
Monitor with aPTT
Half life of 40-50 minutes
Prophylaxis/Treatment in patients with Hep-induced thrombocytopenia
