Coagulation and Anticoagulants Flashcards by Kat Che

What are the three things in Virchow’s Triad

Stasis, hyper coagulability, endothelial injury

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Shortened extremity is a ______ until proven otherwise

hip fracture

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What causes stasis?

immobility, hyperviscosity (polycythemia), paresis (CVA, spinal cord injury), decreased venous returns (varicose, anatomic)

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What causes endothelial injury?

IV catheters, surgery, smoking, trauma, vasculitis

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What are inherited procoagulant conditions?

factor V leiden, prothrombin gene mutation

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What are forms of inherited deficiency of anticoagulants?

protein C deficiency, protein s deficiency, antithrombin deficiency

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What is the intrinsic coagulation cascade?

12->11->9->8->10->5->2

fibrinogen->fibrin from 2

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What is the extrinsic coagulation cascade?

7+TF->10->5->2

fibrinogen to fibrin

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PTT measures? PT measures?

PTT: intrinsic
PT: extrinsic

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When you get down to cross linked fibrin, the ____ kicks to the ____

extrinsic->intrinsic

this is to actually makes the clot

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Protein C and protein S mainly inhibits?

factor 5 and 8

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Warfarin acts at factors?

7, 10, 2, 9

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Most anticoagulants act at factor?

10 (also some at 2)

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What is the MOA of heparin?

bind with antithrombin + accelerates activity. 1000x more favtor inhibition
this inactivates X and II

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Where is heparin sourced from?

bovine or porcine

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What is the metabolism of heparin?

hepatic inactivation. reticule endothelial binding

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Heparin absorption?

very fast IV. peak in 2-4 hours. poorly absorbed in GI

t1/2 1.5hrs

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Heparin Distribution?

widely variable, binds to many plasma proteins. does not cross placenta

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Is Heparin dialyzable?

good for renal disease

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What is heparin used for?

treatment of venous thromboembolism. (DVT + PE)
prophylaxis for above
ACS, acute ischemic stroke (thrombotic or embolic)

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What do you get to measure how the patient is doing on heparin?

aPTT. goal is 1.5-2.5x normal.

CBC- look at hb and platelets

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What are the adverse effects of heparin?

hematologic (hematoma, heparin thrombocytopenia)

dermatologic (erythema, injection site ulcer, local irritation)_

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For Heparin, treatment dosing is ___-based

weight

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what are the G’s and P’s

Gravita: how many times pregnant
P: how many births

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What is the difference between low molecular weight heparin and unfractionated heparin?

Unfrac: binds to factor Xa and thrombin. It wraps 2 in a blankie LMW: binds only Xa, get a more reliable heparin reponse

Do you give warfarin to pregnant patients?

no. its category X and crosses the placenta | craniofacial malformations

LMW is be given ____

SubQ.

LMW heparin has a ______ dose reponse

predictable

LMWH absorption and distribution

Absorb: peak concentration 2-4 hrs. No IM. poor GI Distribution: stable, consistent form patient to patient. equal to blood volume. does not cross placenta

Where is LMWH metabolized?

renal. must keep an eye on the renal function

What is the half life of LMWH? what about fonaparinux?

5-7 hrs. | Fonda is 17-21hrs

What is LMWH indicated for?

VTE (venousthromboembolism) prophylaxis, DVT/PE, ACS (Nstemi, STEMI, unstable angina)

We don't want to give LMWH for _____

acute stroke | embolic->hemorrhagic (we want to be able to shut it off and its gone)

What should you order to monitor LMWH

CBC (platelet, hb/hc) signs of bleeding renal fxn (check Anti-factor Xa)

LMWH Adverse Effects

Dermatologic (erythema, rash, local irritation, injection site ulcer) hematologic (hematoma, heparin induced thrombocytopenia) MSK: osteoporosis other: risk for bruising and minor bleeding

Avoid fondaparinus with _______

renal insufficiency

For heparin, prophylactic doses are ____ and therapeutic doses are _____

set, by weight

What is the MOA of warfarin?

Vitamin K antagonist (inhibit γ carboxylation of factor II, VII, IX, X) also hits protein C and S

What do you order to monitor warfarin?

``` prothrombin time (PT) and international normalized ratio (INR) (we are actually looking t INR) ```

Blood factors need _____ vitamin K to be function?

reduced (then can be used in vitamin K dependent carboxylase)

Warfarin absorption: _______ from GI tract, peak plasma ___ but anti thrombotic effects not seen for ____

rapid, complete absorption from GI tract. <1hours, 3-5 days full effect at 5-10 days NEED a bride therapy

What is warfarin metabolized by?

liver primarily CYPC9 (CYP1A2, CYP2C19, CYP3A4)

Is warfarin dialyzable? What is the t1/2

no, 35 hours

What are indications for warfarin?

treat DVT and PE | Afib, mechanical heart valves (other agents do not have indications here), severe left HF, ACS, myocardial re-infarction

What are contraindications for warfarin?

``` vitamin K is not stable (NPO or otherwise) unable or cannot return to clinic for monitoring active cancer (relative) ```

What are some drug interactions with warfarin?

increased from CYP2CP: bactrim, azoles, amiodarone, phenytoin, cipro primary hemostasis: NSAIDS, clopidogrel, ticagrelor ??: herbals (gingko, ginseng, green tea, garlic) Decreased from CYP2CP: rifampin, St. John's wort

What do you order for warfarin monitoring?

PT/INR often until stable then q4-12 weeks bleeding, new clot the D's: change in diet, dose, disease, drinks, drugs

What are supratherapeutic adverse effects of warfarin

increased bleeding risk, treat with time, vita, FFP, PCC

what are sub therapeutic adverse effects of warfarin

risk of DVT/PE, CVA. bridge back therapeutic if there was a recent event subtherapeutic is not as common with other anticoagulants

What are general adverse effects of warfarin

pregnancy category x, skin necrosis, alopecia

Any antibiotic can alter _____ levels

vitamin K (can make a change to the body's microbe situation)

What are 4 direct oral anticoagulants?

rivaroxaban, apixaban, edoxaban, betrixaban

Dabigatran acts on ____

thrombin

Peak plasma concentration on DOACs is

about the same. 1-4 hours

Which DOAC has the best renal profile

apixaban. great for patient potentially headed to dialysis

Does the different protein binding in DOACs affect metabolism?

What are the major two metabolism methods for DOACs

P-GP substrate. CYP3a4

Dabigatran does not have metabolism at ____

CYP3a4 or cup 2c9

Where are DOAC indicated?

post op hip/knee arthroplasty, nonvalvular afib, VTE, peripheral or coronary artery disease

Do you need to monitor DOAC through labs? ___dosing recommendations are available

no therapeutic monitoring recommending | renal dosing recommendations

DOACs should be avoided in ____

severe hepatic inpairment

What are the two antidotes for DOACs (one specifically for dabigatran)

adexanet | praxbind

betrxaban is only used for

VTE prophylaxis