Show:
Mechanism of Action
Dosing and Monitoring
Reversal Agents
Drug Interactions
Calculations
100

This anticoagulant inhibits vitamin K epoxide reductase, decreasing factors II, VII, IX, and X.

What is warfarin?

100

What test is used to monitor warfarin?

What is international Normalized Ratio (INR)?

100

A patient on Warfarin presents with an INR of >10. What vitamin can be used to bring down a patients INR?

What Vitamin K?

100

This azole antifungal is a strong CYP3A4 inhibitor that can significantly increase levels of factor Xa inhibitors like Apixaban and Rivaroxaban.

*Hint: think G-PACMAN

What is Ketoconazole?

100

A patient weighing 154lbs is prescribed Enoxaparin for treatment of a DVT. The recommended treatment dose is 1 mg/kg every 12 hours. What would this patients dose be?

What is 70 mg?

200

This medication directly inhibits thrombin (factor IIa).

What is dabigatran?

200

For treatment of DVT/PE, this DOAC requires 15 mg twice daily for 21 days before transitioning to 20 mg daily.

What is rivaroxaban?

200

This medication is used to reverse heparin?

What is Protamine Sulfate?

200

If someone is given a CYP inducer, like St. Johns Wart, how will this effect the INR of someone on warfarin?

What is decrease INR?

200
A patient weighing 165 lbs presents with suspected pulmonary embolism and is started on IV unfractionated heparin using the hospital protocol:

  • Bolus: 80 units/kg 

  • Infusion: 18 units/kg/hour

    • Heparin is available as 25,000 units in 250 mL.Question:
    What bolus dose (units) should be administered according to protocol?

    What is 6,000 units?

    300

    What factor do apixaban, rivaroxaban, edoxaban inhibit? 

    What is factor Xa?

    300

    A 78-year-old female with a history of hypertension, prior stroke, and heart failure presents with atrial fibrillation; what is her CHA₂DS₂-VASc score and does this require anticoagulation?

    What is 7 and yes anticoagulation should be started?

    0 males, 1 females: no anticoagulation 

    1 males, 2 females: oral anticoagulation can be considered 

    ≥2 males, ≥3 females, oral anticoagulation 

    300

    This monoclonal antibody fragment reverses the anticoagulant effects of dabigatran?

    What is Idarucizumab?

    300

    This antibiotic is a strong enzyme inducer that can significantly reduce DOAC concentrations, increasing the risk of thrombosis.

    *Hint: Think PS PORCS

    What is rifampin?

    300

    A patient with an INR of 4.8 and no bleeding is instructed to hold 1 dose of warfarin and reduce their weekly dose by 15%; if their prior weekly dose was 40 mg, this is the new weekly dose after adjustment.

    What is 34%?

    400

    What parenteral anticoagulant works by binding antithrombin and inhibiting factor Xa?

    What is fondaparinux?

    400
    A patient with atrial fibrillation is starting Apixaban.Patient characteristics:

  • Age 82 years old

  • Weight 58 kg

  • Serum creatinine 1.4 mg/dL

    • What is the appropriate dose?

    What is 2.5 mg twice daily?

    400

    Despite no missed doses, a patient’s INR is out of range after starting a ‘green smoothie’ diet; do leafy greens cause an increase or decrease in INR?

    What is decrease INR?

    400

    A patient taking Dabigatran starts an antiarrythmic medication that inhibits P-glycoprotein, potentially increasing dabigatran concentrations and bleeding risk.
    Which commonly used antiarrhythmic can cause this interaction?

    What is Amiodarone?

    400
    A patient weighing 80 kg is started on an unfractionated heparin infusion using the standard weight-based protocol:

  • Bolus: 80 units/kg

  • Continuous infusion: 18 units/kg/hour

    • The pharmacy supplies heparin 25,000 units in 250 mL of D5W.Question:

      At what mL/hour rate should the infusion pump be set?

    What is 14.4 mL/hr?

    500

    What are two factors that heparin inhibits to prevent the conversion of fibrinogen to fibrin?

    What is factor IIa and Xa?

    Also factors IXa, XIa, XIIa, plasmin

    500

    This clinical scoring tool used to evaluate the probability of Heparin-Induced Thrombocytopenia (HIT) assigns 0–2 points for four categories: Thrombocytopenia, Timing of platelet fall, Thrombosis, and other causes of thrombocytopenia.

    What is the 4 T-score?

    500

    In life-threatening bleeding due to warfarin, this product is preferred over fresh frozen plasma for rapid reversal

    What is 4-Factor PCC?

    500

    A patient receiving Apixaban for atrial fibrillation starts an anticonvulsant that is a strong CYP3A4 inducer. This interaction may significantly decrease anticoagulant levels and increase thrombosis risk. Which medication is responsible?

    What is Carbamazepine?

    500

    A patient receiving Heparin develops thrombocytopenia with the following findings:

    • Platelet count decreased from 210,000 to 95,000

    • Platelet drop occurred 6 days after starting heparin

    • Patient develops a new pulmonary embolism

    • No other apparent causes of thrombocytopenia

    Using the 4T Score, what is the total score?

    What is

    • Thrombocytopenia >50% → 2 points

    • Timing day 5–10 → 2 points

    • Thrombosis present → 2 points

    • No other causes → 2 points

    Total = 8 → High probability of HIT