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Flashcards in Anticoagulation Deck (149):
0

What's anticoagulant used for?

To prevent blood clots from forming and to keep existing clots from becoming large or expanding

1

What's anticoagulant NOT used for?

They don't break down existing clots (that's done by drugs such as tissue plasminogen activator - tPA).

2

What dx states are anticoagulants used for?

Prevention and tx of DVT/PE

Prevention of stroke

Tx of acute coronary syndrome (ACS)

3

How many pathways are in the coagulation cascade? Name them

2 pathways

Contact activation pathway (Intrinsic pathway)

Tissue factor pathway (Extrinsic pathway)

4

List the factors in the intrinsic pathway

XII, XI, IX, VIII, X, V

5

List the factors in the extrinsic pathway

Tissue factor and VII

6

List the main risk factors for the development of venous thromboembolism. (U)

Surgery

Major trauma

Immobility

Cancer

Previous venous thromboembolism

Pregnancy

Estrogen-containing medications or selective estrogen receptor modulators

7

MOA of UFH, LMWH and fondaparinux? (U)

Bind to antithrombin (AT) -> increases AT activity 1,000 fold

8

Effect of antithrombin (AT)? (U)

AT Inactivates thrombin and other proteases involved in blood clotting, including factor Xa.

9

Which anticoagulant specifically inhibits factor Xa?

LMWHs

10

How does fondaparinux work?

Requires AT binding to selectively inhibit Factor Xa

11

What's the brand name of fondaparinux?

Arixtra

Synthetic pentasaccharide

12

MOA of direct thrombin inhibitors? (U)

Blocks thrombin directly -> decreasing the amt of fibrin available for clot formation

13

What's the importance of direct thrombin inhibitors and heparin-induced thrombocytopenia (HIT) antibodies? (U)

Direct thrombin inhibitors don't cross-react with HIT antibodies

14

Therefore, what's the drug of choice when HIT develops from the use of UFH (and less commonly, LMWHs)? (U)

Direct thrombin inhibitors e.g. argatroban

15

Does Dabigatran (Pradaxa - direct thrombin inhibitor) require blood test to monitor effectiveness? (U)

No.

16

Advantages of Dabigatran (pradaxa) over warfarin?

Pradaxa doesn't require blood tests

Not subjected to food interactions

Has fewer drug interactions than warfarin

17

Disadvantages of Dabigatran (Pradaxa)?

Significant dyspepsia/gastritis

Increased risk of GI bleed

18

List agents that work by inhibiting factor Xa?(u)

Rivaroxaban (Xarelto)

Apixaban (Eliquis)

19

What meds should not be used in pts with prosthetic heart valves? (U)

Dabigatran (Pradaxa)

Rivaroxaban (Xarelto)

Apixaban (Eliquis)

20

MOA of warfarin?(u)

Vitamin K antagonist

21

Role of vitamin k in clotting factors? (U)

Vit k is req for the carboxylate on of clotting factors II, VII, IX, and X.

22

What body requires implementation of policies and protocols to properly initiate and manage anticoagulant therapy? (U)

The Joint Commission's National Patient Safety

23

What's HIT?

Immune-mediated (IgG) drug reaction -> forms antibodies against heparin when it binds to platelet factor 4 (PF 4) -> then binds to Fc receptors on platelets, -> further platelet activation

24

What's the result of untreated Heparin-induced thrombocytopenia (HIT)?

Pro-thrombotic state causing many complications such as venous and arterial thrombosis (HITT)

25

What's the typical onset of HIT?

5-14 days after the start of heparin

OR

Within hours if a pt has been recently exposed to heparin (within last 3 months)

26

Howz HIT diagnosed? (U)

Profound, unexplained drop in platelet count (> 50%) from baseline

27

If HIT is suspected, what should be done if pt is on UFH or LMWH?

Stop all forms of UFH and LMWH, even heparin flushes and heparin-coated catheter

28

If HIT is suspected, what should be done if pt is on warfarin?

Stop warfarin and start Vit K

29

What med is recommended in pts with HIT?

Argatroban

30

When should warfarin be re-started after HIT?

When platelet is at least 150,000/mm3

31

At what dose should warfarin be initiated and how?

Max. of 5mg

Overlap with non-heparin anticoagulant for a minimum of 5 days until INR is within target for 24 hrs

32

What's preferred anticoagulant in pts that req urgent cardiac surgery or PCI?

Bivalirudin

33

MOA of UFH?

Binds to antithrombin (AT)

Inactivates thrombin (Factor IIa) & factor Xa (as well as factors IXa, XIa, XIIa and Plasmin)

Prevents the conversion of fibrinogen to fibrin

34

What's the usual infusion rate of UFH for tx? Concentration?

25,000 units in 250ml in D5W (or 1/2 NS or NS)

100units/ml

35

What's tne strength of UFH used in line flush (HepFlush)?

10 units/mL, 100units/mL

36

Uses of heparin "lock-flushes" (Hep-Flush)

Used to keep IV lines open

Note: there's been fatal errors from choosing incorrect heparin strength

37

What's the dose of UFH for prophylaxis of VTE?

5,000 units SC Q8-12H

38

What's used when using UFH for tx of ACS/STEMI, adjusted body weight or actual body weight?

Actual body weight

39

What's the antidote of UFH? Dosing? Max dose?

Protamine

1mg of protamine per 100 units of UFH

Max dose - 50mg

40

Which UFH pdts contain black box warnings? Why?

Some heparin pdts contain benzyl alcohol.

Theses pdts are contraindicated in neonates and infants

41

SE of UFH?

Bleeding (epistaxis, ecchymosis, gingival, GI etc)

Thrombocytopenia

Heparin induced thrombocytopenia (HIT)

Hyperkalemia

Osteoporosis (with long- pterm use)

42

What SE of UFH is associated with long-term use of UFH?

Osteoporosis

43

Howz UFH monitored?

aPTT

OR

anti-Xa level: 0.3-0.7 units/mL

44

How often is aPPT monitored when pt is on UFH?

6hrs after initiation and Q 6hrs until the therapeutic range of 1.5-2.5 x control

45

What's the therapeutic range of aPTT?

1.5-2.5 x control (pts baseline)

46

What other parameters are monitored when a pt is on UFH? How often?

Platelet count

Hgb

Hct

These are monitored at BASELINE and DAILY to monitor for thrombocytopenia and bleeding

47

Why does UFH have an unpredictable anticoagulant response?

UFH has variable and extensive binding to plasma proteins and cells

48

List the agents that may increase clotting risk. What should be done when starting UFH?

Estrogen and SERMS and other anticoagulants

They should be discontinued if UFH is required

49

MOA of LMWHs?

Work similar to heparin except that the inhibition is much greater for Factor Xa than Factor IIa

50

List agents that are LMWHs.

Enoxaparin (Lovenox)

Dalteparin (Fragmin)

51

What's the brand name of Enoxaparin?

Lovenox

52

What's the dose of Enoxaparin (Lovenox) for prophylaxis of VTE?

30mg SC Q12H or 40mg SC daily

53

What's the dose of Enoxaparin (Lovenox) for prophylaxis of VTE if CrCl < 30mL/min?

30mg SC daily

54

What's the dose of Enoxaparin (Lovenox) for tx of VTE and UA/NSTEMI?

1mg/kg SC Q12H or 1.5mg/kg SC daily

55

What's the dose of Enoxaparin (Lovenox) for tx of VTE and UA/NSTEMI if CrCl < 30mL/min?

1 mg/kg SC daily

56

What's the dose of Enoxaparin (Lovenox) for tx of STEMI? In < 75yrs? Max dose?

< 75 yrs = 30mg IV bolus + 1 mg/kg SC dose followed by 1mg/kg SC Q12H

Max dose: 100mg for the 1st 2 doses ONLY

57

What's the dose of Enoxaparin (Lovenox) for tx of STEMI? In > 75yrs? Max dose?

0.7mg/kg SC Q12H (no bolus)

Max 75mg for the 1st 2 doses ONLY

58

What's the dose of Enoxaparin (Lovenox) for tx of STEMI in CrCl < 30mL/min?

1 mg/kg SC daily

59

What's the dose of Enoxaparin (Lovenox) for tx of STEMI in pts managed with percutaneous coronary intervention (PCI), if last dose was given 8-12 hrs before balloon inflation?

0.3 mg/kg IV bolus

60

What's the brand name of Dalteparin?

Fragmin

61

What's the black box warning Enoxaparin (Lovenox) and Dalteparin (Fragmin)?

Risk of hematomas and subsequent paralysis (for pts receiving neuraxial anesthesia - spinal epidural)

62

Contraindications to use of LMWHs (Enoxaparin - Lovenox; Dalteparin - Fragmin)?

Bleeding

Thrombocytopenia

Hyperkalemia

63

When is monitoring of LMWHs required? (U)

During pregnancy

And

Pts with mechanical heart valves

64

What's monitored during LMWHs use?

Peak anti-Xa levels 4 hours post dose

65

Is Factor Xa inhibitor derived from natural pdt?

Synthetic pentasaccharide

66

MOA of factor Xa inhibitors?

Selectively inhibits factor Xa via antithrombin (AT)

67

Is Fondaparinux a direct inhibitor of factor Xa?

No.

It inhibits Factor Xa via antithrombin (AT), therefore it's an INDIRECT inhibitor of Factor Xa

68

What's the brand name of Fondaparinux?

Arixtra

69

What's contraindication to the use of Fondaparinux (Arixtra)?

Severe renal impairment (CrCl < 30mL/min) (u)

Active major bleed

Bacterial endocarditis

Thrombocytopenia with tve test for anti-platelet antibodies in presence of fondaparinux

70

What's contraindication to the use of Fondaparinux (Arixtra) as prophylaxis?

Body weight < 50kg

71

What's the SE of fondaparinux (Arixtra)?

Bleeding (epistaxis, ecchymosis, gingival, GI etc) (u)

Local inj site rxns (rash, pruritus, bleeding)

Thrombocytopenia

Anemia

Nausea

72

List agents under Factor Xa inh?

Fondaparinux (Arixtra)

Rivaroxaban (Xarelto)

73

What's the brand name for Rivaroxaban?

Xarelto

74

When can missed dose be doubled?

In pts receiving 15mg twice daily, t4 okay to take 2 tablets at once

75

Tx of non-valvular AFib with Rivaroxaban (Xarelto)? CrCl > 50mL/min? 15-50mL/min? < 15mL/min?

CrCl > 50mL/min: 20mg PO daily with EVENING meal

CrCl: 15-50mL/min: 15mg PO daily with EVENING meal

CrCl < 15mL/min: AVOID use

76

Tx of DVT/PE with Rivaroxaban (Xarelto)?

15mg PO bid WITH FOOD x 21 days then 20mg PO daily WITH FOOD

77

When should Tx of DVT/PE with Rivaroxaban (Xarelto) be avoided?

CrCl < 30mL/min

78

Dose of Rivaroxaban (Xarelto) for prophylaxis for DVT (after knee/hip replacement)

10mg PO daily WITHOUT regard to food

79

SE of Rivaroxaban (Xarelto)? (U)

Bleeding

80

What's the brand name of Apixaban?

Eliquis

81

The usual dose of Apixaban (Eliquis) is 5mg bid, when is it halved?

If you have at least 2 of the following:

Age >= 80yrs
Body weight =< 60kg
SCr >= 1.5mg/dL

Give 2.5mg bid

82

When is Apixaban (Eliquis) avoided?

CrCl < 15mL/min

83

Is there an antidote for Fondaparinux (Arixtra), Rivaroxaban (Xarelto), Apixaban (Eliquis)? Monitoring parameter?

No antidote

No monitoring of efficacy required

84

List agents of direct thrombin inhibitors (IV or SC)

Argatroban

Bivalirudin (Angiomax)

Desirudin (Iprivask)

85

List agents of direct thrombin inhibitors (Oral)

Dabigatran (Pradaxa)

86

What's the brand name of bivalirudin?

Angiomax

87

When's direct thrombin inhibitor (DTI) used?

In pts with a hx of HIT

88

Is there cross-reaction of DTI with HIT?

No. No cross rxn with HIT and argatroban, bivalirudin

89

Is there antidote for DTI?

No

90

What's the brand name for Dabigatran?

Pradaxa

91

How to use Dabigatran (Pradaxa)?(u)

Swallow capsules whole

Do not break, chew, crush or open

Do not out in NG tube

92

Howz Dabigatran (Pradaxa) stored?

Keep in original container

Discard 4 months after opening original container

Keep bottle tightly closed to protect from moisture (store in a cool dry place; not bathrooms)

93

SE of Dabigatran (Pradaxa)? U

Dyspepsia

Gastritis-like sx

Bleeding (including more GI bleed)

94

MOA of warfarin?

Competitively inhibits Vit K epoxide reductase (VKORC1) enzyme complex -> depletion of active clotting factors II, VII, IX, and X and proteins C and S

95

What's the brand name of warfarin?

Coumadin, Jantoven

96

Whats the composition of warfarin (Coumadin, Jantoven)?

Racemic mixture of R- and S- enantiomers with S-enantiomer being more potent

97

Howz warfarin (Coumadin/ Jantoven) dosed?

10mg for 1st 2 days, then adjust dose per INR (healthy outpatients)

Elderly - =<5mg

98

What's the color of 1mg warfarin (Coumadin/Jantoven)?

Pink

99

What's the color of 2mg warfarin (Coumadin/Jantoven)?

Lavender

100

What's the color of 2.5mg warfarin (Coumadin/Jantoven)?

Green

101

What's the color of 3mg warfarin (Coumadin/Jantoven)?

Tan

102

What's the color of 4mg warfarin (Coumadin/Jantoven)?

Blue

103

What's the color of 5mg warfarin (Coumadin/Jantoven)?

Peach

104

What's the color of 6mg warfarin (Coumadin/Jantoven)?

Teal

105

What's the color of 7.5mg warfarin (Coumadin/Jantoven)?

Yellow

106

What's the color of 10mg warfarin (Coumadin/Jantoven)?

White

107

SE of warfarin (Coumadin/Jantoven)?

Bleeding

Skin necrosis

Purple toe syndrome

108

What's the monitoring parameter of warfarin (Coumadin/Jantoven)?

INR - 2.0-3.0

109

What's the exceptions to monitoring parameter of warfarin (Coumadin/Jantoven)?

High risk indications e.g. Mechanical mitral valve or mechanical heart valves in both the aortic and mitral position

INR - 2.5-3.5

110

What's the pregnancy category for warfarin? Exception?

X

Women with mech heart valves - preg cat D

111

What's the antidote of warfarin?

Vit K

112

What's the exceptions to 4 weekly testing of the INR?

For pts consistently stable INR, testing can be done up to Q12 weeks

113

T/F? Warfarin is highly protein bound?

True

T4 caution with other highly protein bound drugs that may displace warfarin

114

Which 2C9 inducer causes a LARGE decrease in INR?

Rifampin

115

When should the dose of warfarin be decreased by 30-50%?

When starting Amiodarone

116

List the most common agents with pharmacodynamic interaction with warfarin.

NSAIDs (aspirin, ibuprofen, Celecoxib, etc)

Antiplatelet

Other anticoagulant

SSRIs and SNRIs

117

What's the caveat with the pharmacodynamic drug interaction of NSAIDs, other Antiplatelet, other anticoagulant, SSRIs and SNRIs with warfarin?

These increase bleeding risk BUT INR may be in the usual range or slightly elevated

118

What other med increases bleeding risk with no effect on the INR ?

Ginkgo biloba

119

What's forms of Vit k should be avoided? Why? U

SC inj of Vit k - has a slower onset and can produce variable result

IM inj of Vit k - due to risk of hematoma formulation

120

Which dosage form of Vit K is preferred (when a stat reversal is not required)? U

Oral Vit k (gen at doses of 2.5-5mg)

121

What other dosage form of Vit k is acceptable? Caveat to use?

IV Vit k

Infuse slowly bcuz of anaphylaxis rxn

122

List food high in Vit k

Broccoli, Brussels sprouts

Cabbage, Canola oil, Cauliflower, Chickpeas, Cole Slaw, Collard Greens, Coriander

Endive

Green kale

Lettuce (red leaf or butterhead)

Mustard greens

Parsley

Soybean oil, Spinach, Swiss chard

Tea (green or black), Turnip greens

Watercress

123

How to use Vit K in INR above therapeutic range BUT < 4.5?

Reduce or skip warfarin dose (no Vit k use)

124

How to use Vit K in INR 4.5-10 without bleeding?

Vit K not recommended.

Hold 1-2 doses of warfarin

125

How to use Vit K in INR > 10 without bleeding?

Hold warfarin

Give PO Vit k 2.5-5mg

Resume warfarin at lower dose when INR is therapeutic

126

How to use Vit K in pts with major bleeding from warfarin?

Hold warfarin

Give Vit k 5-10 mg by SLOW IV inj and four-factor prothrombin complex concentration (PCC)

Fresh frozen plasma (FFP) is not recommended

127

When's warfarin stopped before major surgery?

5 days before major surgery

128

Whats the exceptions to stopping warfarin 5 days b4 major surgery?

Mech heart valve

AFib

VTE at high risk of thromboembolism

D/c 24 hrs before surgery

129

What makes up CHADS2 scoring system?

C - CHF
H - HTN
A - Age (> 75)
D - Diabetes
S2 - prior stroke/ TIA

Each risk factor = 1, except stroke/TIA = 2

130

If pt has AFib > 48 hrs, what should be considered before cardioversion?

Target INR 2.0-3.0 should be at target for at least 3 weeks PRIOR to and 4 weeks AFTER cardioversion when normal sinus rhythm is restored

131

If pt has AFib =< 48 hrs, what should be considered before cardioversion?

Start full therapeutic anticoagulation at presentation, do cardioversion and continue full anticoagulation for at least 4 weeks while pt is in normal sinus rhythm

132

What's the antithrombotic therapy for pts with AFib with CHADS2 score = 0?

No therapy

81mg aspirin can be started for those pts wanting anticoagulant therapy

133

What's the antithrombotic therapy for pts with AFib with CHADS2 score = 1?

Oral anticoagulant (Dabigatran -Pradaxa 150mg bid is preferred anticoagulant)

134

What's the antithrombotic therapy for pts with AFib with CHADS2 score >= 2?

Oral anticoagulant (Dabigatran -Pradaxa 150mg bid is preferred anticoagulant)

135

What's options are available for those who can't receive anticoagulants?

Graduated compression stockings (GCS)

Intermittent pneumatic compression (IPC)

136

For Enoxaparin (Lovenox), what should be done with bubbles in the syringe? U

Don't expel air bubbles in the syringe prior to inj (unless your doctor has advised you to do so)

137

How should Dabigatran (Pradaxa) be used?

Swallow capsules whole

138

Howz Dabigatran (Pradaxa) stored?

Keep Dabigatran in original bottle or blister to keep it dry

Don't put Dabigatran in pill boxes or pill organizers

139

How should missed dose of Dabigatran be dealt with?

If next dose is LESS than 6 hours, skip the missed dose

Don't take 2 doses of Dabigatran at the same time

140

What med condition is Rivaroxaban (Xarelto) and Dabigatran (Pradaxa) not recommended for?

Not for pts with artificial heart valves

141

How should Rivaroxaban (Xarelto) be used for AFib?

1 time a day WITH EVENING meal

142

How should Rivaroxaban (Xarelto) be used for blood clot in the veins of legs and lungs?

Once or twice a day as prescribed WITH FOOD

143

If Rivaroxaban (Xarelto) is used 2 times a day, how can a missed dose be used?

You can take 2 doses at the same time

144

How should Rivaroxaban (Xarelto) be used for hip or knee surgery?

Take 1 Rivaroxaban (Xarelto) once daily WITH/WITHOUT food

145

What discoloration may occur with warfarin use?

Purple toe syndrome

146

What's the dose of Lovenox (Enoxaparin) used as a bridge with Warfarin?

Lovenox 80mg SC Q12H

147

List agents that don't increase bleeding risk, while on warfarin?

Calcium with Vit D

Fidaxomicin

148

What's the 1st line tx for a pt with DVT + hx of HIT?

Argatroban

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