Anticoagulants Flashcards Preview

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Flashcards in Anticoagulants Deck (36):
1

Low molecular weight heparins

Enoxaparin (Lovenox), dalteparin (Fragmin), tinzaparin (innohep), Fondaparinux (Arixtra)

2

Direct thrombin inhibitors

Argatroban, lepirudin (Refludan) and bivalirudin (Angiomax)

3

Heparin MOA

Binds to the natural anticoagulant antithrombin and accelerates its enzymatic activity, complex inhibits thrombin as well as other factors

4

What molecules can form the bridge between AT and thrombin

heparin molecules at least 18 saccharide units

5

What will Heparin not do

It will not dissolve an existing blood clot

6

What does Heparin do

Only prevents propagation and growth

7

What is the T1/2 of heparin

it is dose dependent but it usually ranges from 30-90 mins mins

8

Heparin clearance is reduced in who

patients with renal and hepatic dysfunction

9

How do we monitor heparin?

aPTT, ACT, anti-factor Xa activity, or protamine titration assay, aPTT is the most widely used; ACT is most commonly used during coronary angioplasty and CABG surgery

10

ADR's of Heparin

Bleeding, local irritation at injection site, thrombocytopenia, long-term use of heparin, alopecia, priapism, hyperkalemia, elevated ALT/AST and osteoporosis

11

The antidote is available and very effective

Protamine

12

HIT

severe, immune-mediated, drug-induced complication, usually indiacted by 50% drop in platelets or a platelet count ,150,000; typically the drop occurs 5-10 days into treatment

13

What do you do if a patient develops HIT

stop all forms of heparin, be sure to check for flushes, heparin in TPN, and heparin coated catheters, order heparin antibody lab, use a direct thrombin inhibitor or fondaparinux

14

What do you do if the heparin antibody lab is positive?

the patient should never get heparin ever, ever again

15

Heparin clinical uses

treatment of venous thromboembolism, atrial fibrillation, prevention of VTE, acute coronary syndromes, maintaining patent IV line, intraoperative coagulation

16

Low Molecular weight heparin

smaller molecular weight fragment obtained by chemical or enzymatic depolarization techniques of unfractionated heparin, similar to heparin, it prevents formation of thrombi

17

LMWH products commercially available in the US

Enoxaparin (Lovenox), Dalteparin (Fragmin), Tinzaparin (Innohep), last 2 not used

18

Smaller molecular weight prevents what

binding AT and thrombin simultaneously

19

For all three LMWH

routine monitoring is not necessary, T1/2 is 3-6 hours, dose independent renal elimination, subcutaneous bioavailability >90%

20

Routine efficacy monitoring of LMWH is

not recommended

21

What is the most accurated method to monitor efficacy?

Anti-factor Xa levels

22

how often do you measure LMWH

peak level 4 hours post dose at steady state

23

Patients to consider monitoring

weight> 150 kg or ,50 kg, CrCL ,30 ml/min pediatric patients, pregnant patients

24

Enoxaparin (Lovenox)

always adjust dose in renal failure, 1 mg/kg subcut Q12hr, always use actual body weight, don't cap doses in obese

25

ADRs of Enoxaparin (Lovenox)

bleeding (monitor Hgb/HCT), HIT but not as common as heparin

26

Consider use of heparin over LMWH for pt with

obesity, renal failure, surgical candidates, or high risks for bleeding

27

Clinical uses of Enoxaparin (Lovenox)

treatment of VTE, prophylaxis of VTE, prevention of thrombus in Afib, STEMI, NSTEMI

28

Dalteparin (Fragmin)

LMWH, Prophylaxis and treatment of ACS, DVT/PE but not FDA approved for this

29

Tinzaparine (Innohep)

LMWH

30

Fondaparinux (Arixtra)

Factor Xa inhibitor, T1/2= 17-21 hours, will accumulate in renal impairment, no method of monitoring, no reversal agent

31

Clinical uses of Fondaparinux (Arixtra)

VTE prophylaxis, post op joint replacement or abdominal surgery, STEMI and NSTEMI, treatment of PE or DVT

32

Fondaparinux (Arixtra) serves as a great option for people who

have developed HIT

33

Argatroban

a direct thrombin inhibitor, treatment and prophylaxis of HIT, cardiovascular procedures in place of heparin with HIT or suspected HIT, monitor with aPTT and infusion rates adjusted accordingly, $$$, adjust in hepatic

34

Lepirudin (Refludan)

direct thrombin inhibitors, treatment and prophylaxis of HITT, cardiovascular procedures (in place of heparin) with HIT or suspected HIT, use is rare, adjust renal

35

Bivalirudin (Angiomax)

direct thrombin inhibitor, continuous infusion during PCI, IV only $$$$, adjust renal

36

Direct thrombin inhibitors

all given as continuous infusion- short T1/2 (25-75 mins), monitor aPTT to adjust dose