Cardio Exam 4 (McDanel)

• Active cancer/risk of reoccurrence

• Thrombophilias

• Long term immobility

Persistent risk factors

• general anesthesia for less than 30 min

• hospital stay/bedbound for less than 3 days with acute illness

• Prolonged car or air travel

• Use of estrogens or pregnancy

Minor risk factors

• general anesthesia for longer than 30 minutes

• hospital stay/bedbound for more than 3 days with acute illness

• C-section

• major trauma

Major risk factors

VTE treatment agent

DOAC preferred, warfarin is ok

• Hypercoagulability (estrogen, obesity, diseases)

• Hemodynamic changes (immobility)

• Endothelia injury

Virchow’s Triad

3-6 months of treatment of VTE with oral agents is recommended for…

Provoked events due to TRANSIENT risk factors

Extended or indefinite VTE treatment anticoagulation is appropriate for…

Provoked events due to PERMANENT risk factors OR unprovoked without any reversible risk factors (eg. age)

Warfarin goal INR for VTE treatment

2-3

VTE treatment: rivaroxaban and apixaban run in period

Not needed

VTE treatment: Dabigatran and edoxaban run in period

start after 5 or more days of parenteral agent

VTE treatment: warfarin run in period

start with 5 or more days of LMWH

T/F: all oral anticoagulants are equally effective for all thrombophilias

False, warfarin is used in APS

At what CHADS-VASc score should someone be anticoagulated indefinitely in patients at risk of a stroke?

2 for men and 3 for women

Which type of valve replacement can only use warfarin?

Mechanical

Aortic mechanical valve with NO risk factors goal INR

2-3

Aortic mechanical valve WITH risk factors goal INR

2.5-3.5

Mitral mechanical valve goal INR

2.5-3.5

T/F: bioprosthetic valve patients can be on anticoagulation for a little as 3-6 months

True

Which is preferred in afib patients (assuming no other contraindications)? (but both can be used)

DOACs

How long does it take for warfarin to reach steady state?

10-14 days

Which DOAC does NOT undergo CYP metabolism?

Dabigatran

Which oral anticoagulant is considered the “universal anticoagulant for ALL indications and ages, even if not labeled for use”

Warfarin

The following indications are for which drug?

• Stroke reduction (non valvular afib)

• Treatment and prevention of VTE in ages 8+ (no liquid formulation)

• VTE prophylaxis in HIP surgery

Dabigatran

The following indications are for which drug?

• Stroke reduction (non valvular afib)

• Treatment and prevention of VTE in ADULTS ONLY

• VTE prophylaxis in hip AND knee replacement surgery

Apixaban

The following indications are for which drug?

• Stroke reduction (non valvular afib)

• Treatment and prevention of VTE in ALL AGES (liquid formulation)

• VTE prophylaxis in hip AND knee replacement surgery

• Risk reduction in chronic artery diseases (CAD/PAD) in addition to aspirin

Rivaroxaban

Which drug has the following dosing for VTE treatment?

• 10 mg BID for 7 days

• 5 mg BID for 6 months

• 2.5 mg BID after 6 months (if needed)

Apixaban

Which drug has the following dosing for VTE treatment?

• 15 mg BID for 21 days

• 20 mg QD for 6 months

• 10 mg QD after 6 months (if needed)

Rivaroxaban

Which drug has the following dosing for VTE treatment?

• Parenteral agent 5-10 days BEFORE starting

• 150 mg BID

Dabigatran

Which drug has the following dosing for VTE treatment?

• LMWH for 5+ days in ADDITION TO the drug

• INR must be 2 or greater for 24hrs before stopping LMWH

Warfarin

T/F: in afib patients, apixaban dosing is the same as VTE treatment

False, there is no run in period and patients start at 5 mg BID

If two or more of the following are met, which drug must be dose reduced?

• Age 80 or older

• Body weight 60kg or less

• serum creatinine 1.5 or greater

Apixaban, reduce to 2.5 mg BID

Which drug should be reduced if CrCl is less than 50 in afib patients?

Rivaroxaban, to 15 mg QD

Which drug should be reduced if CrCl is between 15-30 in afib patients?

Dabigatran, to 75 mg BID

Which DOAC can be used in patients regardless of renal function, and even in dialysis patients?

Apixaban

DOAC monitoring

Renal function, LFTs, CBC

Typical wafarin starting dose for generally healthy population

5 mg

Initial warfarin monitoring

2-5 days after starting, then 2x a week for 1-2 weeks, then periodically

How frequently should an INR be checked if a patient is not stable (e.g. dose changes or out of range INR)

10-14 days after previous check

How frequently should an INR be checked if a patient is stable?

Every 4 weeks, up to every 12 weeks (not recommended)

How much should an INR rise each day for the first week after starting warfarin?

0.1-0.2

The following do what to INR?

• alcohol binge

• acute illness (fever, diarrhea)

• Decreased vitamin k intake

• significant weight loss

Increase INR

The following do what to INR?

• Increased vitamin k intake

• significant weight gain

• missed doses of warfarin

Decrease INR

T/F: 5-15% change in weekly warfarin dose is reasonable if the INR is slightly out of range

True

T/F: if the INR is 1 pt above target, it is appropriate to hold 3 doses

False, only 1 dose should be held

What is the lowest INR that warfarin reversal (holding/decreasing doses or vitamin k) should be considered?

4.5 or greater

Even if there is no bleeding, at what INR should oral vitamin K be given and warfarin held?

10 or greater

T/F: if there is any bleeding that can not be stopped, four factor complex concentrate is sufficient to stop the bleeding and reverse warfarin

False, vitamin K should always be given as well

The following drugs do what to CYP2C9 and warfarin effect?

• rifampin

• Carbamazepine

• Phenytoin

• Barbiturates

• Nafcillin/dicloxacillin

Induce; decrease

The following drugs do what to CYP2C9 and warfarin effect?

• Sulfamethoxazole/trimethoprim (bactrim)

• Moxifloxacin (just affects warfarin potency)

• Metronidazole

• Azole antifungals

• Amiodarone

Inhibit; increase

T/F: drugs that affect platelets, such as NSAIDs and aspirin, DO affect the INR

False, they only increase bleeding risk so acetaminophen is preferred

T/F: in VTE treatment and prevention in OBESE patients, all DOACs are equally recommended

False, apixaban and rivaroxaban are proven to be safe while dabigatran has a lack of data

In afib patients, when is warfarin preferred over DOACs? (other option is DOACs are preferred)

Warfarin is preferred when the patients has had bariatric surgery

The following drugs are P-gp _____ and _____ DOAC effects

• Dronedarone

• Ketoconazole

• avir antivirals

inhibitors; increase

The following drugs are P-gp _____ and _____ DOAC effects

• Rifampin

• Carbamazepine

• Phenytoin

• St. John’s wort

inducers; decrease

Warfarin to rivaroxaban INR

Start when less than 3

Warfarin to apixaban INR

Start when less than 2

Warfarin to dabigatran

Start when less than 2