Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Heme / Onc > SM_260b: Anticoagulant Therapy for VTE > Flashcards

SM_260b: Anticoagulant Therapy for VTE Flashcards

(56 cards)

Start Studying
1
Q

Describe indirect anticoagulants

A

Indirect anticoagulants

  • Antagonize Vitamin K: warfarin
  • Require antithrombin: heparin, LMWH (dalteparin, enoxaparin), fondaparinux
  • Direct: factor Xa inhibitors (rivaroxaban, apixaban, edoxaban), thrombin inhibitors (dabigatran, argatroban)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe synthesis of Vitamin K dependent clotting factors

A

Synthesis of Vitamin K dependent clotting factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe clotting cascade

A

Clotting cascade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

____ is the main regulator of the carboxylation reaction

A

Vitamin K epoxide reductase is the main regulator of the carboxylation reaction

  • Carboxylated proteins: II, VII, IX, X, C, S, Z are Vitamin K dependent clotting factors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Warfarin causes ____ deficiency in all Vitamin K dependent clotting factors

A

Warfarin causes acquired deficiency in all Vitamin K dependent clotting factors

  • Vitamin K epoxide reductase is main modulator of warfarin response
  • Vitamin K epoxide reductase mutations either increase sensitivity to warfarin or cause hereditary warfarin resistance
  • Homozygosity for missense mutation results in inherited combined deficiency of II, VII, IX, and X
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

____ increases resistance to warfarin

A

VKORC1 increases resistance to warfarin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

____ increases sensitivity to warfarin by decreasing warfarin clearance

A

CYP2C9 increases sensitivity to warfarin by decreasing warfarin clearance

  • Genetic polymorphisms
  • Drug inhibitors / enhancers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe drugs that increase sensitivity to warfarin

A

Increase sensitivity to warfarin

  • Antibiotics: erythromycin, fluconazole, INH
  • Cardiac: amiodarone, propranolol
  • Anti-inflammatories: piroxicam
  • GI: cimetidine, omeprazole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe drugs that increase resistance to warfarin

A

Increase resistance to warfarin

  • Antibiotics: nafcillin, rifampin
  • Anticonvulsants: most
  • Other: sucralfate, cholestyramine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Ginkgo and garlic interactions with warfarin can cause ___

A

Ginkgo and garlic interactions with warfarin can cause bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

St. John’s wort interaction with warfarin can cause ____

A

St. John’s wort interaction with warfarin can cause thrombosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Warfarin is ___-acting and requires ___ to achieve therapeutic levels

A

Warfarin is slow-acting and requires 5 days of dosing to achieve therapeutic levels

  • Full anticoagulation effect occurs when prothrombin levels are reduced to 20%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Warfarin is monitored using ___ and ___

A

Warfarin is monitored using PT and iNR

  • INR standardizes PT results
  • INR = (patient PT / control PT) ISI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Goal INR is ___

A

Goal INR is 2-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

____, ____, and ____ are adverse effects of warfarin

A

Bleeding, teratogenic, and warfarin necrosis are adverse effects of warfarin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

____ reverses effects of warfarin

A

Vitamin K reverses effects of warfarin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe how to manage elevated INR but no bleeding

A

Elevated INR but no bleeding

  • INR > 3-10: hold warfarin
  • INR > 10: hold warfarin, give oral Vitamin K if possible or IV Vitamin K if not
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe how to manage bleeding while on warfarin

A

Bleeding while on warfarin

  • Hold warfarin, give Vitamin K IV
  • Give 4 factor prothrombin complex concentrate or FFP if unavailable
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe heparin

A

Heparin

  • Polymeric, highly sulfated glycosaminoglycan
  • 30-50 saccharide units
  • Pentasaccharide sequence binds antithrombin
  • Longer chains also bind thrombin
  • Inhibits factor Xa and thrombin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe unfractionated heparin

A

Unfractionated heparin

  • Inactivated in gut and given IV or SQ
  • Metabolized in liver and kidney
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe mechanism of unfractionated heparin

A

Unfractionated heparin

  1. Binds antithrombin to activate it and enhance its effects
  2. Heparin-antithrombin complex inhibits thrombin
  • Thrombin bound to fibrin is protected from heparin - prevents further clot formation but doesn’t dissolve clot
  • Inhibits smooth muscle proliferation and angiogenesis
  • Bound form usually inactive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Unfractionated heparin acts ___

A

Unfractionated heparin acts immediately

  • aPTT and/or UFH anti-Xa levels are used to monitor dose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

____, ____, and ____ are adverse reactions of unfractionated heparin

Study These Flashcards
A

Bleeding, heparin-induced thrombocytopenia, and osteoporosis are adverse reactions of unfractionated heparin

  • Mild inhibition of aldosterone may increase potassium
25
Heparin-induced thrombocytopenia occurs when \_\_\_
Heparin-induced thrombocytopenia occurs when antibodes bind heparin-platelet factor 4 complex and agglutinate platelets, leading to paradoxical thrombosis despite low platelets * Discontinue heparin immediately and start alternative anticoagulants (direc thrombin inhibitors)
26
Describe advantages and disadvantages of unfractioned heparin
Unfractioned heparin * Advantages: effect immediate, 5000 U sc q8-12h is safe and effective thromboprophylaxis for low risk patient, reversed by protamine * Disadvantages: protein binding so effect must be monitored, heparin-induced thrombocytopenia
27
LMWH works primarily through \_\_\_
LMWH works primarily through potentiation of antithrombin effect on factor Xa (lacks tail to bind thrombin)
28
\_\_\_\_, \_\_\_\_, and ____ are examples of LMWH
Dalteparin, enoxaparin, and tizaparin are examples of LMWH
29
LMWH has ___ subcutaneous absorption than heparin
LMWH has better subcutaneous absorption than heparin
30
Describe advantages and disadvantages of LMWH
LMWH * Advantages: better subcutaneous absorption than heparin, less binding to plasma proteins, more predictable effect so monitoring not routinely needed; outpatient use feasible; infrequently causes heparin-induced thrombocytopenia or osteoporosis * Disadvantages: renally cleared, expensive, subcutaneous injection
31
Fondaparinux is a ____ that only has ____ activity
Fondaparinux is a synthetic 5 saccharide binding site of antithrombin that only has anti-Xa activity activity * Given subcutaneously and has high bioavailability * Minimal protein binding and no monitoring needed * Once daily subcutaneous injection because half-life of 17 hours * Minimal interaction with platelets
32
Describe advantages and disadvantages of fondaparinux
Fondaparinux * Advantages: once daily dosing, no monitoring required, equivalent in efficacy * Disadvantages: not used in renal failure and low body weight due to risk of bleeding, no reversal agent, expensive
33
Direct thrombin inhibitors ___ and \_\_\_
Direct thrombin inhibitors inactive clot-bound and soluble thrombin and do not require antithrombin as a co-factor * Derived from medicinal leech * Not inactivated by platelet factor 4 or heparinase
34
\_\_\_\_, \_\_\_\_, and ____ are direct thrombin inhibitors
Bivalirudin, argatroban, and dabigatran are direct thrombin inhibitors
35
Bivalirudin is used for ___ and has a ___ half-life
Bivalirudin is used for thrombus prevention in coronary interventions and has a very short half-life (25 minutes)
36
Argatrobin reversibly binds to ___ and is used primarily in \_\_\_
Argatrobin reversibly binds to catalytic site of thrombin and is used primarily in treatment of heparin-induced thrombocytopenia * IV infusion * Monitor with aPTT * Conversion to warfarin problematic because argatroban prolongs PT
37
Direct acting oral anticoagulants are ___ and have \_\_\_
Direct acting oral anticoagulants are oral and have more predictable pharmacokinetics that obviate the need for routine monitoring * All approved for prevention of thrombosis in atrial fibrillation, treatment, and prevention of DVT and PE
38
Direct acting oral anticoagulants are \_\_\_\_, \_\_\_\_, \_\_\_\_, \_\_\_\_, and \_\_\_\_
Direct acting oral anticoagulants are rivaroxaban, apixaban, edoxaban, betrixaban, and dabigatran etexilate
39
Anti-Xa DOACs are \_\_\_\_, \_\_\_\_, \_\_\_\_, and \_\_\_\_
Anti-Xa DOACs are rivaroxaban, apixaban, edoxaban, and betrixaban
40
Direct thrombin inhibitor DOAC is \_\_\_
Direct thrombin inhibitor DOAC is dabigatran etexilate
41
Compare DOACs
DOACs
42
Compare DOACs and warfarin
DOACs and warfarin
43
\_\_\_\_ is used for reversal of dabigatran
Idarucizumab is used for reversal of dabigatran * Humanized monoclonal antibody fragment (Fab) that binds specifically to dabigatran * Much higher affinity for dabigatran than thrombin
44
\_\_\_ is used for reversal of rivaroxaban and apixaban
Andexanet alpha is used for reversal of rivaroxaban and apixaban * Acts as a factor Xa decoy and retains high affinity for all direct FXa inhibitors * Change of serin to alanine to eliminate catalytic activity and prevent prothrombin cleavage
45
Thrombolytics \_\_\_
Thrombolytics activate plasminogen to form plasmin in order to accelerate thrombus breakdown * Indications: acute coronary thrombosis, massive PE, thrombotic stroke
46
tPA is a \_\_\_
tPA is a thrombolytic
47
Cullen's sign is \_\_\_
Cullen's sign is periumbilical bleeding with anticoagulation
48
Turner's sign is \_\_\_
Turner's sign is flank bleeding with anticoagulation
49
If bleeding occurs with anticoagulation, ___ and \_\_\_
If bleeding occurs with anticoagulation, stop anticoagulant and other offending agents contributing to bleeding (aspirin, NSAIDs) and use a reversal agent
50
Protamine is a reversal agent for \_\_\_
Protamine is a reversal agent for UFH * Partly reverses LMWH
51
Vitamin K and 4-factor prothrombin complex concentrate are reversal agents for \_\_\_
Vitamin K and 4-factor prothrombin complex concentrate are reversal agents for warfarin
52
Idarucuzimab is a reversal agent for \_\_\_
Idarucuzimab is a reversal agent for dabigatran
53
Andexanet alpha is a reversal agent for \_\_\_\_
Andexanet alpha is a reversal agent for anti-Xa inhibitors
54
Acute management of thrombosis involves \_\_\_
Acute management of thrombosis involves beginning anticoagulant when thrombosis is suspected or diagnosed
55
Describe long-term management of VTE
Long-term management of VTE * Everyone with acute VTE needs 3 months of anticoagulation * After 3 months * If provoked VTE: stop * If unprovoked: indefinitely as long as risk of recurrent clot outweighs risk of bleeding
56
Summarize the anticoagulants
Anticoagulants

Heme / Onc (41 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions