Anticoagulants

Question 1

8 Anticoagulants

WHED RADF

Answer 1

Warfarin
Heparin
Enoxaparin - LMWH
Dalteparin - LMWH
Fondaparinux - Indirect Xa + Antithrombin
Dabigatran - IIa 
Rivaroxaban- Xa
Apixaban - Xa

Question 2

MOA of Warfarin

Answer 2

Inhibits Vitamin K reductase activity

which inhibits clotting factor formation in liver

Question 3

Factors which require vitamin K for synthesis

Answer 3

II, VII, IV, X

Question 4

About how long until anticoagulant effects of warfarin take hold

Answer 4

15-20 hours
(factors must drop by 25%)

measured by INR **goal = 2-3 **

Question 5

Warfarin for ACS

Answer 5

After Aspirin / Clopidogrel has been used OR when there are additional comorbidities

Question 6

Warfarin for DVT / PE

Answer 6

2nd line

2016 CHEST guideline?

Question 7

Warfarin 1st line

Answer 7

A fib

Mechanical Valv

Question 8

Warfarin drug interactions

Answer 8

NSAIDs
Antiplatelet agents
SSRIs
St John's Wort
Tramadol
CoQ10
Ginger

Question 9

Warfarin ABX interactions

Answer 9

Cephalosporins
Bactrim
Metronidazole
Fluoroquinalones
Amoxacillin
Doxycycline 
Fluconazole

Question 10

Tx Warfarin toxicity

Answer 10

Stable patients: single dose activated charcoal, if recently ingested. Vitamin K1, IV slow drip

Question 11

INR for holding warfarin dose

Answer 11

INR > 4.5 - 10, no bleeding

Question 12

INR >10, no bleeding

Answer 12

hold warfarin, give vitamin K po

Question 13

Weird warfarin issues

Answer 13

Purple toe syndrome

Skin necrosis - protein C deficiency, breasts buttocks abdo thigh

Question 14

Unfractionated Heparin MOA

Answer 14

Accelerating binding of Antithrombin III to factor IIa

Question 15

Time to anticoagulation effect w Heparin

Answer 15

1-3 hours

short half life, Rapid metabolism in liver

Question 16

Anticoagulants in STEMI

Answer 16

Aspirin, chewed 160-325mg, ASAP

P2Y Inhibitor (Clopidogrel, Prasugrel, Ticagrelor) - especially patients undergoing PCI or Fibrinolysis

UFH if undergoing PCI
UFH, Enoxaparin, or Fondaparinux if Fibrinolysis

Question 17

LMWH and Fondaparinux

Answer 17

Enoxaparin
Dalteparin
Tinzaparin

Fondaparinux

Sub Q, doesn’t need monitoring, less risk of HIT and bleeding

Question 18

Heparin antidote

Answer 18

Protamine

1mg for 100 u heparin
30-60 s onset

Question 19

Heparin ADRs

Answer 19

Bleeding
HIT
Osteoporosis
Elevated LFTs

Question 20

Alternative anticoagulant in patients w Type II HIT

Answer 20

Lepirudin
Argatroban
Fondaparinux

Question 21

Anticoags for Afib > 48 hrs or unknown duration

Answer 21

Warfarin (INR 2-3)

LMWH (Enoxaparin, Dalteparin, Fondaparinux)

or Dabigatrin

for 3 weeks before cardioversion, continued Dabi or Warf for a least 4 weeks after

Question 22

Anticoags for Afib <48 hours

Answer 22

UFH or LMWH (Enoxaparin, Dalteparin, Fondaparinux) at presentation prior to cardioversion, continued at least 4 weeks after

Question 23

Long term anticoagulation w nonvalvular Afib, CHADs2 risk

Answer 23

Dabigatran (DOAC) must have CrCl > 30

Rivaroxaban (Xa) best for high risk

Apixaban (Xa)

Question 24

VTE /PE Anticoags

Answer 24

LMWH (Enoxaparin, Dalteparin, Tinzaparin, Fondaparanux

UFH (if CrCL <30)

Warfarin or Rivaroxabin (Xa) for maintenance

Question 25

Rivaroxaban / Apixaban (Xa) ADRs

Answer 25

Spinal /epidural hematoma, risk w spinal procedures or injuries

Question 26

Reduced efficacy in NVAF in patients with NORMAL renal function

Answer 26

Edoxaban

Question 27

When to choose Warfarin over newer agents

Answer 27

Patients w Renal Insufficiency, Prosthetic Heart Valves Cost

Question 28

Higher GI bleed risk w which agents?

Answer 28

Dabigatran, Rivaroxaban

Question 29

CHADS 2 VASC treatment

Answer 29

``` Score = 0 No treatment or ASA 75 – 325 mg/day Score = 1 Anticoagulant preferred Or ASA + clopidogrel (Plavix) Score > 1 Oral anticoagulant (warfarin INR 2 – 3, dabigatran, apixaban or rivaroxaban) ```

Question 30

P2Y12 Inhibitors, Thienopyridines

Answer 30

Clopidogrel (Plavix) | Prasugrel

Question 31

P2Y 12 Inhibitors, Thienopyridines (Clopidogrel, Prasugrel) MOA

Answer 31

Irreversibly blocks platelet aggregation and adhesion by blocking ADP receptor

Question 32

Clopidogrel and poor metabolizers and drug interactions

Answer 32

efficacy dependent on activation to an active metabolite by CYP2C19, 30-50% of people Drug Interactions CYP 2C19 Omeprazole (Prilosec), esomeprazole (Nexium)

Question 33

** Prasugrel contraindications**

Answer 33

Active bleed | Past TIA or CVA

Question 34

Other PY2 Platelet Inhibitors *Reversible*

Answer 34

Ticagrelor - Hepatic metabolism CYP 3A4 Cilostazol

Question 35

Anticoag indicated for intermittent claudication

Answer 35

Cilostazol *contraindicated in HF*

Question 36

PAD anticoag treatment

Answer 36

ASA or Clopidogrel, if symptomatic, or asympt but ABI <90 Statins, treat HTN (ACEI, or ARB)

Question 37

Fibrinolytic Agents

Answer 37

TPA Alteplase Reteplase Tenecteplase (TNKase)

Question 38

TPA MOA

Answer 38

Activates fibrin-enhanced conversion of plasminogen to plasmin

Question 39

TPA Absolute Contraindications

Answer 39

Absolute contraindications h/o intracranial hemorrhage, ischemic stroke or closed head injury within past 3 months Intracranial malignancy Intracranial or intraspinal surgery within past 2 months Suspected Aortic dissection Active bleeding Severe uncontrolled hypertension

Question 40

Clot Buster Antidotes

Answer 40

Aminocaproic acid tranexamic acid (Cyclokapron) Lysine analogs

Question 41

Dabigatran drug interactions

Answer 41

Rifampin - Avoid using together Amiodarone Ketoconazole Verapamil Proton pump inhibitors