Anticoagulation Therapy Collaboration

Question 1

Warfarin MOA

Answer 1

Inhibits activation of vitamin K dependent clotting factors

Question 2

What is the target INR

Answer 2

2-3

Question 3

Factors that can affect INR

Answer 3

Drugs
Missed/extra doses
Acute illness (diarrhea)
Dietary changes (vitamin K)
AECHF/edema
Increased alcohol intake

Question 4

What is bridging?

Answer 4

The practice of substituting a therapeutic dose of heparin for warfarin when warfarin is interrupted for surgery

Question 5

Why do we need to do bridging?

Answer 5

To shorten the period during which the patient is not therapeutically anticoagulated and at high risk for thromboembolism
Takes 5 days to get out of system, and then 5-7 to get into therapeutic range

Question 6

Warfarin antidote

Answer 6

Vitamin K

Combo of factors 2/7/9/10

Question 7

Benefit of apixiban

Answer 7

Somewhat lower bleeding risk than warfarin

Question 8

Dabigatran

Answer 8

Least drug interactions
Has an antidote
Dyspepsia is not uncommon
Not studied or approved as monotherapy for acute VTE (give 5 days LMWH alone, then start DOAC alone)

Question 9

Benefits of Xa inhibitors

Answer 9

Rivaroxaban is a once daily drug
Apixaban least dependent on renal excretion
Rivaroxaban and apixaban studied and approved as monotherapy for acute VTE treatment