Anticoagulation Flashcards

1
Q

What is an embolus?

A

When a clot or a piece of a clot travels to another location

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2
Q

What factors does warfarin inhibit?

A
SNOT
Seven
Nine
Ten (10)
Two
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3
Q

What factors do rivaroxaban, apixaban, edoxaban, and betrixaban inhibit?

A

Xa

All have xa in their name

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4
Q

What factors do UFH inhibit?

A

Xa and IIa

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5
Q

What factors do LMWH inhibit?

A

Xa and IIa (more X than II)

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6
Q

What factors do argatroban, bivalirudin, and dabigatran inhibit?

A

IIa (thrombin)

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7
Q

DOAC vs Warfarin

Which has less drug drug interactions?

A

DOAC

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8
Q

DOAC vs Warfarin

Which has shorter half life?

A

DOAC

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9
Q

DOAC vs Warfarin

For which one is dosing based on the indication and liver/hepatic function?

A

DOAC

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10
Q

DOAC vs Warfarin

Which one is dosed based on INR?

A

Warfarin

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11
Q

When to use DOAC vs Warfarin

A

DOAC: stroke prophylaxis in afib if CHADSVASC >/ 2 (men) or 3 (women); VTE treatment
Warfarin: if moderate/severe mitral stenosis or mechanical heart valve
If patient has cancer and VTE, use LMWH

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12
Q

What factor does fondaparinux inhibit?

A

Xa indirectly via antithrombin

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13
Q

What is the drug of choice in someone with HIT?

A

argatroban

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14
Q

What decrease in Hgb can indicate a bleed?

A

> /2

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15
Q

What drugs increase bleeding risk?

A

Anticoagulants, antiplatelets, NSAIDs, natural products (e.g. ginkgo), SSRIs, SNRIs

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16
Q

Unfractionated heparin MOA

A

binds to antithrombin (AT) which inactivates factor IIa (thrombin) and Factor Xa and prevents the conversion of fibrinogen to fibrin

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17
Q

Unfractionated heparin prophylaxis and treatment of VTE dosing - use what body weight?

A

Prophylaxis: 5000 units SQ q8-12h
Treatment: 80 units/kg IV bolus then 18 units/kg/hr
Use total body weight

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18
Q

Unfractionated heparin CI, Warnings, SE

A

CI: active bleeding, severe thrombocytopenia, history of HIT
Warnings: Fatal medication errors
SE: Bleeding, thrombocytopenia, HIT, alopecia, hyperkalemia, osteoporosis (long term use)

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19
Q

Unfractionated heparin antidote

A

protamine

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20
Q

Why should you not given unfractionated heparin IM?

A

Risk of hematoma

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21
Q

Low molecular weight heparin drugs and MOA

A

MOA: bind to antithrombin which inactivates factor Xa and Factor IIa
Drugs: Enoxaparin, dalteparin

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22
Q

LMWH BBW, CI, SE

A

BBW: patients receiving neuraxial anesthesia (epidural, spinal) or undergoing spinal puncture d/t risk of hematoma and paralysis
CI: History of HIT, active bleed
SE: BLeeding, anemia, injection site reactions, decreased platelets

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23
Q

When should you monitor anti Xa levels when using LMWH?

A

In pregnancy

Also obesity, low body weight, pediatrics, elderly, or renal insufficiency

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24
Q

LMWH antidote

A

protamine

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25
What medications are used to break down clots but have a low risk of bleeding?
Fibrinolytics
26
HIT is an immune mediated reaction that involves which immunoglobulin
IgG
27
HIT vs HITT
Heparin induced thrombocytopenia | Heparin induced thrombocytopenia + thrombosis
28
Typical onset of HIT
5-14 days
29
If a patient is diagnosed with HIT and they are on warfarin, what should you do and why?
D/c warfarin and give vitamin K | Warfarin use with low platelet count has a high correlation with warfarin-induced limb gangrene and necrosis
30
When can you start warfarin in someone who was diagnosed with HIT?
When platelets have recovered to >150,000 | Overlap with non-heparin anticoagulant for at least 5 days until INR is within goal for >24 hours
31
Apixaban (Eliquis) dosing for Nonvalvular afib Treatment of DVT/PE
Nonvalvular afib: 5mg PO BID (2.5mg in certain populations) | Treatment of DVT/PE: 10mg PO BID x 7 days then 5mg PO BID
32
What to do if patient missed a dose of | Apixiban (Eliquis)
Take immediately on the same day and BID administration should be resumed Do NOT double up
33
What to do if patient missed a dose of | Rivaroxaban (Xarelto)
Administer ASAP on same day | If taking BID can double up on a dose - just maintain total daily dose
34
What to do if patient missed a dose of | Edoxaban (Savaysa)
Take immediately on the same day | Do NOT double up
35
What to do if patient missed a dose of | Betrixaban (Bevyxxa)
Take immediately on the same day | Do NOT double up
36
Rivaroxaban dosing for Nonvalvular afib Treatment of DVT/PE
Nonvalvular Afib: - CrCl >50: 20mg daily with dinner - CrCl 15-50: 15mg daily with dinner - CrCl <15: avoid use Treatment of DVT/PE: 15mg PO BID x 21 days then 20mg daily - CrCl <30: avoid use
37
Should rivaroxaban be taken with or without food?
Take dose 15mg and greater with food
38
Edoxaban dosing for Nonvalvular afib Treatment of DVT/PE
``` Nonvalvular Afib - CrCl > 95: do NOT use - CrCl 51-95: 60 mg daily - CrCl 15-50: 30 mg daily - CrCl <15: not recommended Treatment of DVT/PE: 60mg daily starting 5-10 days after parenteral anticoagulation ```
39
Oral direct factor Xa inhibitors BBW, CI, warnings, SE
BBW: patients receiving neuraxial anesthesia (epidural or spinal) or undergoing spinal puncture - risk for hematoma and paralysis; increased risk of thrombotic events with premature discontinuation CI: active pathological bleeding Warnings: Not recommended with prosthetic heart valves SE: well tolerated, bleeding
40
Antidote for apixaban and rivaroxaban
Andexanet alfa (Andexxa)
41
When to d/c oral direct factor Xa inhibitors for elective surgery
Rivaroxaban, edoxaban: d/c 24 hours prior to elective surgery Apixaban: d/c 28 hours prior to elective surgery with moderate-high bleeding risk or 24 hours before low bleeding risk
42
Fondaparinux BBW, CI, SE
BBW: Patients receiving neuraxial anesthesia (epidural, spinal) or undergoing spinal puncture are at risk of hematomas and subsequent paralysis CI: severe renal impairment (CrCl < 30 mL/min), active bleed, bacterial endocarditis SE: bleeding, anemia, local injection site reactions, thrombocytopenia, hypokalemia, hypotension
43
Fondaparinux antidote
None
44
Conversion from warfarin to another oral anticoagulant | Stop warfarin and convert to ____ when INR is ____
Rivaroxaban <3 Edoxaban 2.5 or less Apixaban <2 Dabigatran <2
45
Conversion from oral Xa inhibitors (apix, edox, and rivaroxaban) to warfarin
Overlap Xa inhibitor with warfarin until INR is therapeutic | Stop Xa inhibitor and start parenteral anticoagulant and warfarin at next scheduled dose
46
Conversion from dabigatran to warfarin
Start warfarin 1-3 days before stopping dabigatran
47
What medications are direct thrombin inhibitors?
Dabigatran Argatroban Bivalirudin
48
What to do if patient missed a dose of | Dabigatran (Pradaxa)
Take ASAP unless it is within 6 hours of the next dose | Do NOT double up
49
Dabigatran (Pradaxa) dosing for Nonvalvular afib Treatment of DVT/PE
Nonvalvular afib 150mg BID CrCl 15-30: 75mg BID CrCl <15: no recommendations Treatment of DVT/PE 150mg BID starting 5-10 days after parenteral anticoagulation CrCl < 30: no recommendation
50
Dabigatran (Pradaxa) BBW, CI, SE
BBW: Patients receiving neuraxial anesthesia (epidural, spinal) or undergoing spinal puncture are at risk of hematomas and subsequent paralysis; premature d/c increases thrombotic risk CI: active pathological bleeding, mechanical heart valve SE: dyspepsia, gastritis-like symptoms, bleeding
51
Dabigatran (Pradaxa) antidote
idarucizumab (praxbind)
52
What DOAC needs to be dispensed in it's original container?
Dabigatran (Pradaxa)
53
What medications are safe to use in patients with HIT?
argatroban and bialirudin
54
Warfarin MOA
competitively inhibits vitamin K epoxide reductase (VKORC1) enzyme complex causing depletion of active clotting factors II, VII, IX, and X
55
What to do if a patient misses a dose of warfarin?
Take ASAP on the same day | Do not double dose the next day
56
Warfarin BBW, CI, warnings, SE
BBW: major or fatal bleeding CI: pregnancy (except with mechanical heart valve at high risk of clot), uncontrolled HTN, recent eye surgery or CNS, possible miscarriage Warnings: tissue necrosis/gangrene, HIT, presence of CYP2C9*2 or *3 alleles and/or polymorphism of VKORC1 gene may increase bleeding risk SE: bleeding/bruising, purple toe syndrome
57
What is the typical warfarin INR goal? When should it be higher?
Typical: 2-3 | Higher if mechanical mitral valve or 2 mechanical heart valves
58
Warfarin antidote
Vitamin K (phytonadione)
59
What warfarin tablet color is associated with each dose?
``` Please Let Greg Brown Bring Peaches To Your Wedding Pink 1 Lavender 2 Green 2.5 Brown 3 Blue 4 Peach 5 Teal 6 Yellow 7.5 White 10 ```
60
What medications decrease INR while on warfarin
aprepitant, bosentan, carbamazepine, phenobarbital, phenytoin, primidone, rifambin, licorice, and st. john's wort
61
What medications increase INR while on warfarin
amiodarone, azole antifungals, capecitabine, etravirine, fluvastatin, fluvoxamine, macrolide, abx, metronidazole, bactrim
62
What foods are high in vitamin K?
Broccoli, brussel sprouts, cabbage, spinach, tea (green/black) Green leafy veggies
63
What natural supplements increase bleeding risk while on warfarin?
Garlic, ginger, ginkgo, ginsent, glucosamine | Bromelain, don quai, vitamin D, high dose fish oil, willow bark, wintergreen oil
64
What natural supplements decrease bleeding risk while on warfarin?
Alfalfa, green tea, coenzyme Q10, st john's wort
65
Protamine sulfate indication, BBW, SE
Indication: UFH/LMWH reversal BBW: hypersensitivity SE: hypotension, bradycardia, flushing, anaphylaxis
66
Idarucizumab indication, warnings, SE
Indication: dabigatran (Pradaxa) reversal Warning: thromboembolic risk SE: HA, low K, delirium, constipation, fever
67
Andexanet alfa indication, BBW, SE
Indication: apixaban and rivaroxaban reversal BBW: thromboembolic risks, ischemic events, cardiac arrest, sudden death SE: injection site reaction, DVT, ischemic stroke, UTI, pneumonia
68
Vitamin K (phytonadione) indication, BBW, SE
Indication: warfarin reversal BBW: hypersensitivity reactions (rare) SE: anaphylaxis, flushing, rash, dizziness
69
Four factor prothrombin complex concentrate (Kcentra) indication, BBW< CI, warnings, SE
Indication: warfarin reversal BBW: arterial and venous thromboembolic complications CI: disseminated intravascular coagulation (DIC) and known HIT Warnings: made from human blood and may carry risks of transmitting infectious agents SE: HA, N/V/D, arthralgia, hypotension, low K, thrombotic events
70
When to use IV vs PO vitamin K to reverse warfarin?
INR <4.5 - skip warfarin dose and monitor INR 4.5-10 and no bleeding: hold 1-2 doses warfarin and monitor INR >10 and no bleeding - hold warfarin and give vitamin K INR at any level and major bleeding 5-10mg IV vitamin K and Kcentra
71
When to stop warfarin before major surgery
Stop ~5 days before surgery Can bridge with LMWH or UFH (d/c LMWH 24 hours before surgery and UFH 6 hours before surgery) Resume warfarin 12-24 hours after surgery
72
How long should VTE be treated for?
3 months if known cause of VTE | if unknown cause of VTE can treat for longer if not high bleeding risk
73
What medications are preferred in patients without cancer? With cancer?
Without: dabigatran, rivaroxaban, apixaban, and edoxaban With: LMWH
74
Patients with mechanical heart valves and atrial fibrillation/flutter are anticoagulated with what?
Warfarin only because they are high risk
75
What does CHADSVASc stand for?
``` CHF HTN Age>/75 years - 2 Diabetes Stroke/TIA prior - 2 Vascular disease (MI, PAD, aortic plaque) Age 65-74 Sex, female ```
76
What are the CHADSVASc risk categories and recommended therapies?
``` Score 0 (M) or 1 (F): no anticoagulation recommended Score 1 (M) or 2 (F): Oral anticoagualtion may be considered Score 2 (M) or 3 (F): Oral anticoagulation recommended; DOAC preferred ```
77
What anticoagulant medications are preferred in pregnancy? Which are contraindicated?
Preferred: LMWH (DOC), UFH, pneumatic compression CI: warfarin (may use during second/third trimester and change back to LWMH close to delivery) DOACs have not been studied and are not recommended
78
Which anticoagulant should be kept in the original bottle and not put in a pill organizer?
dabigatran