Treatment of Thromboembolic Disease

Question 1

Prothrombin Test

Answer 1

Extrinsic Pathwawys

Question 2

Activated Partial Thromboplastin Time (aPTT or PTT)

Answer 2

Intrinsic pathways

Question 3

INR

Answer 3

Changes in clotting factors II, VII, X

Question 4

Anti-Factor Xa

Answer 4

Reflext changes in Xa activity

Question 5

Heparin Initial Dose

Answer 5

80 unit/kg IV then 18 u/kg/h

Question 6

Heparin Monitoring

Answer 6

aPTT 1.5-2.5 X mean normal control
Q6H
CBC: hemoglobin and platelets

Question 7

Heparin AE

Answer 7

Hemorrhage

Protamine by slow IV push

Question 8

1 mg of protamine sulfate will

Answer 8

Neutralize approximately 100 units

Question 9

Major bleed =

Answer 9

2 g decrease in Hgb, require transfusion

Question 10

Enoxaparin Dose

Answer 10

1 mg/kg SQ Q12H (CrCl <30 Q24H)

Question 11

Dalteparin Dose

Answer 11

200u/kg SQ Q24H

Question 12

LMWH Monitor

Answer 12

Anti-Xa in obesity, renal dysfunction, pregnacy

CBC (Hgb, plt) and S/Sx bleeding

Question 13

LMWH Contraindication in?

Answer 13

Patients with epidural/spinal puncture

Question 14

Fondaparinux Dose

Answer 14

100kg 10 mg SQ QD

CrCl <30

Question 15

Warfarin Dose

Answer 15

5-10 mg 65, renal insuff, heart failure, liver disease, high bleed risk
Give at bedtime!

Question 16

Starting Warfarin

Answer 16

Bridge with UFH or LMWH
Overlap at least 5 days (doesn’t work on clotting factors already made)
Due to depletion of endogenous anticoagulants

Question 17

SNOT

Answer 17

7, 9, 10, 2

Shortest to longest half life

Question 18

Mechanical valve (mitral valve) INR

Answer 18

2-3

Question 19

Long-term Duration

Answer 19

VTE and cancer
Recurrent VTE
VTE and hypercoagulable state and
Mechanical valve

Question 20

Warfarin Monitoring

Answer 20

INR daily for 7 days until steady state
INR 1-3d during initiation
CBC

Question 21

Warfarin INR Recheck

Answer 21

1-2 wks after one INR within therapeutic range
4 weeks after two
12 weeks if stable

Question 22

Warfarin adjusts

Answer 22

Based on weekly dose

Adjust 5-10% based on INR

Question 23

Warfarin AE

Answer 23

Skin necrosis
Purple toe syndrome
Teratogenic

Question 24

Drug interaction with warfarin INR

Answer 24

Bactrim
Amiodarone
Metronidazole
Azole
Rifampin
Barbiturates
Vitamin K

Question 25

Drug interaction with warfarin Platelets

Answer 25

Nsaids
Cox 2 inhibitors
Aspirin
SSRIs

Question 26

Amiodarone

Answer 26

decrease warfarin dose by 25-50% and monitor INR weekly for 6 weeks

Question 27

Bactrim

Answer 27

Decrease warfarin dose by 50% and monitor for 1-2d

Question 28

Rifampin

Answer 28

Increase warfarin dose by 25-50% and monitor for 1-2d

Question 29

Vitamin K

Answer 29

Supratherapeutic INR management

Question 30

INR 4.5-10

Answer 30

Not vitamin K unless major bleed

Hold doses and decrease by 5-10%

Question 31

INR >10

Answer 31

Give Vitamin K (2.5-5mg PO)

If not, develop spontaneous bleed

Question 32

Serious Bleed

Answer 32

Hold warfarin

Vit K 5-10 mg slow IV infusion

Question 33

Rivaroxaban (Xarelto)

Answer 33

VTE 15 mg PO BID x 3 wks –> 20 mg PO Qd 3 months

No reversal agent

Question 34

Apixaban (Eliquis)

Answer 34

Factor Xa Inhibitor
10 mg PO BID X 7d –> 5 mg PO BID x 6 months –> 2.5 mg BID x 12 months
Pros: No monitoring, fixed
Cons: no reversal and BID

Question 35

Dabigatran (Pradaxa)

Answer 35

IIa inhibitor
Afib/VTE/PE: 150 mg PO BID after 5-10 days of IV anticoag
Pros: No monitoring, no food interactions, fewer drug interactions
Cons: BID, no reversal