Oral Anticoagulant
Which clotting factor is inhibited by dabigatran?
Factor IIa (direct thrombin inhibitor)
Which of the following is a contraindication to the use of Heparin?
a. H/o HIT
b. Recent procedure
c. Allergy to iodine
d. Severe renal impairment
a. H/o HIT
A 57 year old woman develops new atrial fibrillation while inpatient for upcoming surgery. Not on any anticoagulation prior. Which is the BEST heparin infusion to start?
a. Acute VTE (PTT)
b. Standard Bridge (PTT)
c. Standard Bridge (Anti-Xa)
d. Acute VTE (Anti-Xa)
c. Standard Bridge (Anti-Xa)
No history of DOAC, and new atrial fibrillation
Name the four components of the 4T Score.
Acute Thrombocytopenia, Timing, Thrombosis, Other Cause of thrombocytopenia
Both intrinsic and extrinsic pathways meet at a shared point to continue coagulation, the common pathway. At which factor do they meet?
Factor X
Both pathways can independently activate X --> Xa
Which is the ONLY oral anticoagulant indicated for VALVULAR atrial fibrillation?
**BONUS - What is VAVLULAR atrial fibrillation?
Warfarin
BONUS - Atrial fibrillation in the presence of mitral stenosis or artificial heart valve.
Which of the following is preferred to use in patients with h/o of ESRD on hemodialysis?
a. Enoxaparin
b. Heparin
c. Argatroban
d. Bivalirudin
d. Heparin
An 80 year old female presents with NSTEMI to ED. PMH of pAF (apixaban), HTN, prior CAD (last stent 2020). No baseline Anti-Xa available, which heparin nomogram would you recommend starting?
A. Acute VTE (PTT)
B. ACS (Anti-Xa)
C. ACS (PTT)
D. Standard bridge (Anti-Xa)
C. ACS (PTT)
ACS + unknown/suspected DOAC use
A 68 year old male with PMH of A fib, CKD4, is started on dabigatran. His CrCl is 14 ml/min. What is an appropriate next step in management?
a. Continue dabigatran dosing
b. Reduce dabigatran dosing by 50%
c. Switch to Apixaban
d. He does not need anticoagulation therapy
C. Switch to Apixaban
Dabigatran should be avoided in CrCl < 15 ml/min
A 95 year old female presents to the ER with NEW DVT. Given her SCr of 2.0 mg/dL (baseline) and weight of 84 kg. What anticoagulation/dose would you recommend?
A. Apixaban 2.5 mg BID
B. Rivaroxaban 15 mg BID x 7 days, followed by 20 mg daily with dinner
C. Apixaban 10 mg BID x 7 days, followed by 5 mg BID
D. Apixaban 10 mg BID x 7 days, followed by 2.5 mg BID
C. Apixaban 10 mg BID x 7 days, followed by 5 mg BID
**Dose reduction on apixaban only pertinent for atrial fibrillation
A 50 year old patient is started on rivaroxaban for VTE treatment. What is the advantage of this drug choice over warfarin?
a. Longer half life
b. Less risk of bleeding
c. Fewer drug interactions
d. More frequent monitoring required
c. Fewer drug interactions
Typical dosing for therapeutic enoxaparin is 1 mg/kg Q12H or 1.5 mg/kg Q24. For a patient with BMI of 57.4, per our CPA what is the recommended initial dose of enoxaparin?
0.8 mg/kg Q12
**Obtain enoxaparin peak (4 hours after dose) after 3rd/4th dose
An 60 year old male presents with NSTEMI to ED. PMH of pAF (apixaban), HTN, prior CAD (last stent 2020). Baseline Anti-Xa level 0.54. Which heparin nomogram would you recommend starting?
A. Acute VTE (PTT)
B. ACS (Anti-Xa)
C. ACS (PTT)
D. Standard bridge (Anti-Xa)
C. ACS (PTT)
*Baseline Anti-Xa 0.54 - recommended to start PTT if baseline Anti-Xa >0.3
A patient is started on apixaban for stroke prevention with history of atrial fibrillation. What is an advantage of this drug over rivaroxaban?
a. Lower bleed risk
b. Lower HIT risk
c. Longer half-life
d. No monitoring required
a. Lower bleed risk
Apixaban found to have lower bleed risk compared to warfarin/rivaroxaban
A 60 year old male presents to ED with a SAH s/p mechanical fall. Patient is on warfarin for a h/o Afib. INR on admit is 3.8, with plan to take patient to OR. What would you recommend for reversal of warfarin.
A. IV Vitamin K 10 mg x 1
B. Kcentra 1500 IU x 1
C. IV Vitamin K 10 mg + IV Kcentra 1500 IU
D. Kcentra 25 U/kg x1, followed by additional dose 24 hours post-op
C. IV Vitamin K 10 mg + IV Kcentra 1500 IU
Vitamin K onset = 1-2 hours, peak 12-14 hours
Kcentra onset = 30 minutes or less, duration of effect ~12-24 hours
What clotting factors are inhibited by warfarin?
Warfarin inhibits factors II, VII, IX and X
PLUS protein C + S
Name for each parenteral anticoagulant the clotting factor inhibited and monitoring?
A. Argatroban
B. Heparin
C. Bivalirudin
Argatroban - direct thrombin (IIa) - PTT
Heparin - potentiates antithrombin (IIa, Xa) - PTT/Anti-Xa
Bivalirudin - direct thrombin (IIa) - PTT
A patient was started on heparin infusion (PTT) for history of atrial fibrillation on apixaban prior. Baseline Anti-Xa >1.10. When would you recheck an Anti-Xa level AND when would you transition to Anti-Xa monitoring?
A. 96 hours after apixaban dose - Anti-Xa <0.3
B. 24 hours after apixaban dose - Anti-Xa <1.10
C. 48 hours after apixaban dose - Anti-Xa <0.7
D. 72 hours after apixaban dose - Anti-Xa <0.3
C. 48 hours after apixaban dose - Anti-Xa <0.7
A patient with a h/o HIT is transitioning from argatroban to warfarin therapy. INR today is 4.5, argatroban is stopped. How would you recommend dosing warfarin?
a. Continue current warfarin regimen, no need to check any additional INR
b. Recheck INR 4-6 hours after argatroban stopped, if INR 2-3 continue current warfarin regimen
c. Hold all therapy INR is supratherapeutic
d. Recheck INR 4-6 hours after argatroban stopped, if INR <2 continue current warfarin regimen
b. Recheck INR 4-6 hours after argatroban stopped; if INR 2-3 continue current warfarin regimen
**Argatroban/bivalirudin can both cause false increase in INR - imperative to check INR 4-6 hours after infusion stopped to ensure INR remains therapeutic
Name the reversal agent for each anticoagulant.
A. Warfarin
B. Heparin
C. Dabigatran
D. Apixaban
A. Vitamin K / Kcentra
B. Protamine
C. Idarucizumab
D. Andexxa-alfa / Kcentra
A 80 year old female patient presents to the ED with new SOB, found to have bilateral pulmonary embolism. What oral anticoagulant is the best choice to treat her PE?
PMH: HTN, GIB (10+ years ago), CKD IV
A. Rivaroxaban 10 mg BID x 14 days, followed by 15 mg daily
B. Apixaban 10 mg BID x 7 days, followed by 5 mg BID
C. Enoxaparin bridge until warfarin therapeutic (INR 2-3)
D. Apixaban 5 mg BID x 7 days, followed by 2.5 mg BID
B. Apixaban 10 mg BID x 7 days, followed by 5 mg BID
A 65 year old male patient develops a NEW DVT despite being on a therapeutic heparin infusion for the past 10 days as bridge/post-op care. Since admit platelets have decreased from 250K to 44K. What do you recommend to treat the patients NEW DVT?
A. Switch to enoxaparin 1.5 mg/kg Q24
B. Continue heparin infusion
C. Switch to argatroban infusion
D. Switch to fondaparinux injection
C. switch to argatroban infusion
- Monitor PTT, 4T Score = 7
A 70 year old female presents to the ED with NEW atrial fibrillation? Unknown history given AMS. Baseline labs were obtained and Anti-Xa level = 0.35. Which heparin nomogram would you recommend starting?
A. Standard bridge (Anti-Xa)
B. Standard bridge (PTT)
C. ACS (Anti-Xa)
D. ACS (PTT)
B. Standard bridge (PTT)
**Per CPA start PTT if baseline Anti-Xa >0.3
A 55 year old male presents with dehydration/AKI to ED. PMH significant for atrial fibrillation (Xarelto PTA). Given the following information what would your recommendation be regarding the patients home rivaroxaban dose? ABW 245 kg, SCr 3.5 mg/dL, IBW 63.8 kg.
a. Decrease rivaroxaban to 15 mg w/ dinner
b. Continue rivaroxaban 20 mg w/ dinner
c. Change to dabigatran 75 mg BID
d. Change to apixaban 2.5 mg BID
b. Continue rivaroxaban 20 mg w/ dinner
**Per the ROCKET-AF Trial when calculating the CrCl for rivaroxaban use the actual body weight of the patient. CrCl <50 mL/min recommends dose reduction to 15 mg daily with dinner
Patient presents to ED with new GIB. On treatment dose enoxaparin 100 mg Q12 PTA, bridge for upcoming procedure. Last dose of enoxaparin was ~4 hours prior to presentation. What reversal agent would you use and what dose?
A. Kcentra 1500 IU x 1
B. Vitamin K PO 10 mg daily x 5 days
C. Protamine 100 mg IV x 1
D. Protamine 50 mg IV x 1
C. Protamine 100 mg IV x 1
First 8 hours - 1 mg protamine for 1 mg of enoxaparin
Hour 8-12 - 0.5 mg protamine for 1 mg of enoxaparin