Anticoagulation & Blood Disorders: Anticoagulation Flashcards by Patryk Lasiuk

Two pathways of coagulation cascade

Contact activation pathway (intrinsic) = minor pathway
Tissue factor pathway (extrinsic) = activated by tissue damage/trauma

How well did you know this?

Not at all

Perfectly

Warfarin inhibits factors

2,7,9,10

How well did you know this?

Not at all

Perfectly

DOAC work on factor

How well did you know this?

Not at all

Perfectly

Direct thrombin inhibitors (DTI) work on…

Thrombin IIa

How well did you know this?

Not at all

Perfectly

UFH and LMWH work on factors….

Xa and Thrombin IIa

How well did you know this?

Not at all

Perfectly

DOACs vs Warfarin

Use warfarin if moderate-severe mitral stenosis or mechanical heart valve in stroke prevention for AF

Use warfarin if pt has antiphospholipid syndrome or mechanical heart valve in VTE treatment

How well did you know this?

Not at all

Perfectly

UFH antidote

protamine

How well did you know this?

Not at all

Perfectly

UFH ppx VTE dose

5,000 units SubQ Q8-12h

How well did you know this?

Not at all

Perfectly

UFH txm VTE dose

80 units/kg IV bols, 18unit/kg/hr infusion

use TBW

How well did you know this?

Not at all

Perfectly

UFH txm ACS/STEMI dose

60/unit/kg IV bous, 12 unit/kg/hr inusion

use TBW

How well did you know this?

Not at all

Perfectly

UFH monitoring

aPPT
Platelets, Hgb, Hct baseline and daily ( dec platelets by 50% possible HIT)

How well did you know this?

Not at all

Perfectly

LMWH boxed warnings

receiving epidural/spinal anesthesia or spinal puncture due to risk of hematomas and subsequent paralysis

How well did you know this?

Not at all

Perfectly

LWMH CI

history of HIT
active major bleed

How well did you know this?

Not at all

Perfectly

LMWH ppx VTE dosing

30mg Q24hr or 40mg Q24hr

30mg Q 24hr if CrCl < 30

How well did you know this?

Not at all

Perfectly

LMWH txm VTE, UA and NSTEMI

1mg/kg Q12hr
1.5mg/kg QD (in patient VTE only)

1mg/kg Q24hr if CrCl < 30

How well did you know this?

Not at all

Perfectly

LMWH txm STEMI in pts < 75yrs of age

30mg IV bolus + 1mg/kg dose + 1mg/kg Q12 (max 100mg 1st 2 doses)

CrCl < 30 = 30mg IV bolus + 1mg/kg dose + 1mg/kg Q24hr

How well did you know this?

Not at all

Perfectly

LMWH txm STEMI in pts > 75yrs old

0.75mg/kg Q12hr

CrCk < 30 = 1mg/kg Q24hrs

How well did you know this?

Not at all

Perfectly

LMWH antidote

protamine

How well did you know this?

Not at all

Perfectly

LMWH monitoring

can monitor anti-Xa levels

How well did you know this?

Not at all

Perfectly

4Ts score

probability of HIT calculated using this score

Thrombocytopenia = unexplained drop of > 50% in platelet count
Timing = HIT onset usually 5-10 days after start heparin
Thrombosis = new suspected/confirmed thrombosis, skin lesions

if HIT is likely, ELISA is done and thats confirmed with a serotonin release assay or heparin-induced platelet aggregation assay

How well did you know this?

Not at all

Perfectly

HIT management

If suspected or confirmed, stop all heparin/LMWH, if on warfarin then stop and admin Vitamin K.

rapid-acting non-heparin anticoagulant used (argatroban)

Dont restart warfarin until platelets > 150K

if urgent surgery or PCI required, bivalirudin preferred agent

How well did you know this?

Not at all

Perfectly

Apixaban nonvalvular AF (stroke ppx) dosing

5mg BID

2.5mg BID IF 2 of the following: > 80, < 60kg or SCr < 1.5

How well did you know this?

Not at all

Perfectly

Apixaban txm of DVT/PE dosing

10mg BID for 7 days, then 5mg BID

Extended phase (after > 3 months txm) - 2.5mg BID

How well did you know this?

Not at all

Perfectly

Apixaban ppx DVT (after hip/knee replacement)

2.5mg BID (12 days for knee or 35 days for hip)

How well did you know this?

Not at all

Perfectly

Edoxaban has reduced efficacy in pts with CrCl that is

> 95

Apixaban and Rivaroxaban antidote is

andexanet alfa (Andexxa)

Rivaroxaban should be taken with...

food for doses > 15mg 10mg doses can be taken without regard to food

Rivaroxaban nonvalvular AF (stroke ppx)

CrCl > 50 = 20mg QD w/ evening meal CrCl 15-50 = 15mg QD w/ evening meal CrCl < 15 = dont use

Rivaroxaban txm fo DVT/PE

15mg BID X 21 days, then 20mg QD w/ food Extended phase (> 3 months) 10mg QD CrCl < 30 = dont use

Rivaroxaban ppx DVT (after knee/hip replacement) and VTE (acute ill medical pts)

10mg QD X 12 days (knee), 35 days (hip), 31-39 days (acute ill medical patients) CrCl < 30 = dont use

Rivaroxaban reduction in risk of major CVD events in CAD/PAD

2.5mg BID in combo w/ low dose aspirin CrCl < 15 = avoid use

Edoxaban non valvular AF (stroke ppx)

CrCl > 95 = dont use CrCl 51-95 = 60mg QD CrCl 15-50 = 30mg QD CrCl < 15 = dont use

Edoxaban txm of DVT/PE

60mg QD, 5-10 days after parenteral anticoag IF CrCl 15-50, BW < 60kg, on certain P-gp inhib = 30mg QD Dont use CrCl < 15

Time cut offs for DOAC and surgery

Apixaban = stop 48hrs before if mod-high bleeding risk, 24hrs if low Rivaroxaban/Edoxaban = stop 24hr before

Converting from warfarin to other anticoagulant

Rivaroxaban when INR < 3 Edoxaban when INR < 2.5 Apixaban when INR < 2 Dabigatran when INR < 2

Fondaparinux ppx of VTE

> 50kg 2.5 mg QD < 50 kg = CI

Fondaparinux txm of VTE

< 50kg = 5mg QD 50 - 100kg = 7.5mg QD > 100kg = 10mg QD

Fondaparinux CrCl cut offs

CrCl 30-50 = use caution CrCl < 30 = CI

Dabigatran CI

treatment of pts with mechanical prosthetic heart valves

Dabigatran Side effects

Dyspepsia Gastritis like symptoms Gi bleeding

Dabigatran antidote

idarucizumab (Praxbind)

Dabigatran nonvalvular AF (stroke ppx)

150mg BID CrCl 15-30 = 75mg BID CrCl < 15 = dont use

Dabigatran txm of DVT/PE and reduction of recurrent DVT/PE risk

150mg BID, start 5-10 days after parenteral anticoag CrCl < 30 = dont use

Dabigatran ppx of DVT/PE following hip replacement

110mg Day 1, 220mg QD CrCl < 30 = avoid use

Dabigatran notes

have to dispense in OG container, and throw out after 4 months of opening Swallow capsule whole, dont give in NG tube

Argatroban notes

Safe for history of HIT or active HIT No antidote

Warfarin CI

Pregnancy, unless mechanical heart valve and high risk for TE

Warfarin Warnings

tissue necrosis/gangrene HIT VKORC1 gene or CYP2C9*2/3 allele may inc bleeding

Warfarin INR goal for most indications

2-3

Warfarin INR goal of 2.5-3.5 for....

high risk indications such as mechanical mitral valve, 2 mechanical heart valves, or mechanical aortic valve with 1 additional risk factor

Warfarin Antidote

Vitamin K Kcentra can be used with vitamin K for rapid reversal

Foods high in Vitamin K will do what to INR

decrease, so would have to increase warfarin dose (Dark leafy greens) important to keep consistent vitamin K balance in diet when on warfarin

Using Vitamin K for over anticoagulation

INR > 4.5 w/o bleeding = reduce or skip dose, monitor INR INR 4.5 - 10 w/o bleeding = hold 1-2 dose, monitor INR INR > 10 w/o bleeding = hold warfarin, give Vitamin K Major bleeding = hold warfarin, give Vitamin K & Kcentra

Any VTE caused by surgery or reversible risk factor should be treated for....

3 months

If VTE is unprovoked, should be treated for....

longer than 3 months of low-mod risk of bleeding keep at 3 months if high

If 2 episodes of unprovoked VTE then consider....

long term treatment

Medications CI in patients with hx of or current VTE

estrogen containing medications selective estrogen receptor modulators

pts w/o cancer, dabigatran or DAOC preferred over....

warfarin for 1st 3 months of txm for DVT in leg or PE

pts w/o cancer, what is preferred over warfarin/LMWH?

DOACs

CHA2DS2-VASc Score

C = CHF H = HTN A2 = Age > 75 = 2 pts D = Diabetes S2 = Prior stroke/TIA = 2 pts V = Vascular Disease (prior MI, PAD, aortic plaque) A = age 65-74 = 1 pt Sc = Sex, Female = 1 pt

HAS-BLED score

H = HTN > 160 A = abnormal liver or renal function = 1-2 S = prior stroke B = Bleeding tendency or predisposition L = labile INR if on warfarin E = elderly > 65 D = Drugs (aspirin/NSAIDs) excess alc use = 1-2

Anticoagulation in pregnancy

LMWH preferred