Anticoagulants Flashcards
(103 cards)
1
Q
Warfarin target
A
II, VII, IX, X
K-dependent factors
2
Q
Target of UFH and LMWH
A
Xa, IIa
3
Q
Target of Dabigatran
A
IIa
4
Q
Target of Rivaroxaban
A
Xa
5
Q
Target of fondaparinux
A
Xa
6
Q
Target of argatroban
A
IIa
7
Q
IV direct thrombin inhibitors
A
Argatroban and Bivalrubin
8
Q
Drugs that don’t cross-react with HIT antibodies
A
DTIs
9
Q
Who establishes protocols to initiate and manage anticoagulant therapies
A
Joint Commission’s National Patient Safety Goals
10
Q
MOA of UFH
A
Inactivates thrombin (IIa) and factor Xa (IXa, XIs, XIIIa, and plasmin) → preventing the conversion of fibrinogen to fibrin
11
Q
Difference between UFH and LMWH in terms of selectivity
A
UFH: equal anti-Xa and anti-IIa activity
LMWH: anti-Xa > anti-IIa
12
Q
UFH dosing for prophylaxis VTE
A
5000 units SC Q8-12H
13
Q
UFH dosing for VTE Tx
A
80 units/kg IV bolus; 18 units/kg/hr infusion
TBW
14
Q
UFH dosing for ACS/STEMI
A
60 units/kg IV bolus; 12 units/kg/hr infusion
TBW
15
Q
CI of UFH
A
Active bleed
16
Q
ADR and warning of UFH
A
Fatal med errors
Bleeding (epistaxis, bruising, gingival, GI), thrombocytopenia (HIT), hyperkalemia
17
Q
What to monitor for UFH
A
aPTT and anti-Xa level 6 hrs after initiation and Q6H until therapeutic
aPTT 1.5-2xcontrol (therapeutic range)
Platelets ↓ >50% → HIT
18
Q
What are heparin lock-flushes
A
Not for anticoagulants → only used to keep IV lines open
19
Q
Antidote for heparin
A
Protamine
20
Q
MOA of LMWH
A
Inactivate factor Xa > factor IIa
21
Q
LMWH dosing for VTE prophylaxis
A
30 mg SC Q12H or 40 mg QD
22
Q
LMWH dosing for VTE and UA/NSTEMI
A
1 mg/kg Q12H
OR
1.5 mg/kg QD (inpatient VTE)
CrCl < 30: 1 mg/kg QD
TBW
23
Q
LMWH dosing for STEM <75YO
A
30 mg IV bolus + 1 mg/kg SC dose → 1 mg/kg Q12H (max 100 mg for 1st 2 SC doses)
CrCl <30: 30 mg IV bolus + 1 mg/kg SC dose → 1 mg/kg QD
TBW
24
Q
LMWH dosing for STEM ≥75YO
A
0.75 mg/kg Q12H (Max 75 mg for first 2 doses only)
CrCl <30: 1mg/kg QD
TBW
25
BBW of LMWH
Neural anesthesia (spinal, epidural) → ↑ risk of hematoma and subsequent paralysis
26
CI of LMWH
Bleeding, Hx of HIT
27
ADR of LMWH
Bleeding, anemia, inj rx, decreased platelets
28
Monitoring of LMWH
anti-Xa Q4H post dose
29
Counseling on administration of LMWH
Don't expel air bubble from syringe
30
Enoxaparin
Lovenox
30
What is HIT
Immune-mediated IGG drug reactions: immune system forms antibodies against heparin bound to platelet factor 4 → platelet activation → prothrombic state
31
How do you assess HIT risk
4Ts
32
What are the 4Ts
Thrombocytopenia: platelet ↓ >50%
Timing: 5-10days
Thrombosis
Other causes: ruling out other causes
33
Management of HITT
1. Stop heparin and LMWH, discontinue warfarin and administer vitamin K
2. Use rapid acting non-hearing anticoagulants IV DTI (argatroban)
3. Don't use warfarin until platelets are ≥150000 → overlap with non-heparin for 5 days until INR is at target for 24 hrs
4. Urgent cardiac surgery or PCI → bivalrudin is preferred
34
Direct factor Xa inhibitors
Apixaban
Rivaroxaban
Edoxaban
35
Indirect factor Xa inhibitors
Fondaparinux
36
Apixaban
Eliquis
37
Rivaroxaban
Xarelto
38
Endoxaban
Savaysa
39
Antidote for LMWH
Protamine
40
Antidote for Factor Xa inhibitors
Apixaban and Rivaroxaban: andexanet alfa (Andexxa)
41
Duration of DVT prophylaxis after hip and knee replacement
Hip: 35 days
Knee: 12 days
42
Apixiban dosing for nonvavular AF
5 mg PO BID
2 of the filling for low dose: ≥80 YO, ≥1.5 sCr, ≤60 kg
- 2.5 mg PO BID
43
Apixiban dosing for DVT/PE treatment
10 mg PO BIF x 7 days then 5 mg PO BID
44
Rivaroxaban nonvalvular AF dosing
With evening meal
45
Rivaroxaban DVT/PE tx dosing
15 mg PO BID x 21 days → 20 mg PO QD with food
CrCl <15: Avoid use
46
Rivaroxaban DVT prophylaxis dosing
Give first dose 6-10 hrs after surgery
47
Counseling of Rivaroxaban
Doses ≥15 mg take with food
If taking 15 mg BID and miss one dose → take 2 15 mg at once
If <30 mg, take immediately on the same day
48
CI of edoxaban
CrCl >95
CrCl <15
49
Edaxaban DVT and PE treatment dosing
60 mg QD start after 5-10 days of parenteral anticoagant
50
BBW of DOAC (Xa) and fondaparinux
Neuraxial anesthesia (epidural, spinal) → increased risk of hematoma and subsequent paralysis
51
CI of DOAC (Xa)
Active bleeding
Not recommended for valves or antiphospholipid syndrome
52
When do you DC DOAC (Xa) prior to surgery
Rivaroxaban and edoxaban: DC 24H
Apixaban: DC 48 HR
53
CI of fondaparinux
CrCl <30
54
How to convert Warfarin to PO anticoagulants
Stop warfarin and convert to:
- Rivaroxaban when INR <3
- Edoxaban when INR ≤2.5
- Apixaban when INR <2
- Dabigatran when INR <2
55
How to switch from PO Xa inhibitor to warfarin
Stop Xa inhibitor → start parenteral anticoagulants and warfarin at next scheduled dose (bridge)
56
How to switch from Dabigatran to warfarin
Start warfarin 1-3 days before stopping dabigatran
57
Dabigatran
Pradaxa
58
Missed dose for dabigatran
Take immediately unless its within 6 hrs
59
When to initiate dabaigatran for DVT and PE treatment
5-10 days of parenteral anticoagulantion
60
CI of dabigatran
Mechanical prosthetic heart valve
61
ADR of dabigatran
Dyspepsia, gastritis-like sx, bleeding
62
Antidote for dabigatran
Idarucizumab (Praxbind)
63
BBW of dabigatran
Neuraxial anesthesia (epidural, spinal) → increased risk of hematoma and subsequent paralysis
64
Counseling on administration of dabigatran
Dispense in original container and discard 4 months after opening
Swallow capsule whole, don't open, don't administer in NG tube
65
Labs that are elevated with Dabigatran
INR and aPTT
66
Indication for IV direct thrombin inhibtors
HIT → patient undergoing PCI or at risk for HIT
67
MOA of warfarin
VKORC1 enzyme complex inhibitor and decreases activity of factor II, VII, IX, and X, protein C and S
68
Starting dose of warfarin for healthy individuals
≤10 mg QD for 2 days then check INR
69
Indications for lower warfarin dose
≤5 mg: elderly, malnourished, drugs that ↑ levels, liver disease, HF, high risk bleeding
70
CI of warfarin
Pregnancy with mechanical heart valve
71
Warning of warfarin
Tissue necrosis/gangrene, don't use for HIT, purple toe syndrome, presence of CYP2C9*2 and *3 or VKROC1 polymorphisms → ↑ bleeding
72
ADR of warfarin
Bleeding/bruising, skin necrosis
73
Indication for INR Goal of 2.5-3.5
Mechanical mitral valve, 2 mechanical heart valves
74
Indication for INR goal of 2-3
Most indications: VTE, AF, bioprosthetic mitral valve, mechanical aortic valve, antiphospholipid syndrome
75
Antidote for warfarin
Vit K
76
More potent warfarin isomer
S
77
Natural products that ↑ bleeding risk
Chondroitin, dong quai, fish oils,
Garlic, ginger, ginseng, glucosamine, ginkgo
Vitamin E, willow bark
78
Foods that contain vit K
Spinach
Brocolli
Brussel sprouts
Collard green
Kale
(Dark leafy greens)
79
How often to monitor warfarin once stable
4-12 weeks (12 weeks is preferred)
80
Dosing of protamine for IV UFH
1 mg protamine for 100 units of heparin → give within 2-2.5 hrs
Max: 50 mg
81
Dosing of protamine for LMWH
1 mg protamine for 1 mg enoxaparin
82
ADR of vitamin K
Anaphylaxis
83
Administration of vitamin K
Light protection
SC/IM is not recommended
Form: PO or IV
84
What is in Kcentra
Factor II, VII, IX, X, protein C and S
Administered with Vit K
85
Factor VIIa recombinant
NovoSeven RT
86
Warfarin reversal dosing
PO Vit K (2.5-5 mg): non major bleeding
IV Vit K: serious bleeding
87
What to do if INR is <4.5 without bleeding
Reduce or skip dose of warfarin
88
What to do if INR is 4.5-10 without bleeding
Hold 1-2 doses of warfarin
89
What to do if INR is >10 without bleeding
Hold warfarin. Give PO Vit K 2.5-5 mg
90
What to do with major bleeding
Hold warfarin. Give IV vit K 5-10 mg and Kcentra or FFP
91
When to discontinue warfarin prior to surgery
5 days
92
When to DC LMWH prior to surgery
24h
93
How to diagnose VTE
Ultrasound or D-dimer
94
How to prevent VTE
Compression stockings, calf muscle exercises, frequent ambulation,
95
Drug CI with a hx for VTE
SERM, estrogen products
96
Preferred VTE treatment for patients without cancer
DOACs x 3 months > warfarin
97
Preferred VTE treatment for patients withcancer
Factor Xa inhibitors > Dabigatran and LMWH
98
Anticoagulation timeline in patient undergoing cardioversion
AF >48hrs or unknown duration: AC 3 weeks prior to and 4 weeks after cardioversion
AF ≤48 hrs and elective cardioversion: perform cardioversion then 4 weeks fo AC
99
What is the CHADS Vasc Score
Estimate of stroke risk in patients with AF
CHF
HTN
Age ≥75 (2+)
Diabetes
Stroke hx
Vascular disease
Age 65-74 (1+)
Female (1+)
≥3 females and ≥2 males: DOACs are recommended
100
What is the HASBLED score
Determines patientrisk for bleeding while on anticoagulants
HTN
Abnormal liver or renal
Stroke hx
Bleeding tendency
Labile INR (warfarin)
Elderly age >65YO
Drugs (ASA, NSAIDS, alcohol)
101
Preferred AC in pregnancy
LMWH
Check anti-Xa levels
102
Where to inject Lovenox
Right or left side of abdomen (2 inches for belly button)
Don't rub
