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 8.5 but no signs of bleeding. What is the most appropriate management strategy?
What is hold warfarin and give oral vitamin K if bleeding risk is high
100
This azole antifungal is a strong CYP3A4 inhibitor that can significantly increase levels of factor Xa inhibitors like Apixaban and Rivaroxaban.
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 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
Bactrim is a common antibiotic is well known to increase INR in what anticoagulant
What is warfarin
200
A patient weighing 128 kg presents with suspected pulmonary embolism and is started on IV unfractionated heparin using the hospital protocol:
Bolus: 80 units/kg (maximum bolus 10,000 units)
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 10,000 units
300
What factor do apixaban, rivaroxaban, edoxaban inhibit?
What is factor Xa
300
A pregnant patient receiving therapeutic Enoxaparin for treatment of a pulmonary embolism requires laboratory monitoring to ensure appropriate anticoagulation. Which laboratory test should be obtained 4 hours after the dose to assess the anticoagulant effect?
What is a Anti Xa level
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.
What is rifampin
300
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
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
Weight 58 kg
Serum creatinine 1.4 mg/dL
What is the appropriate dose?
What is 2.5 mg twice daily
400
In life-threatening bleeding due to warfarin, this product is preferred over FFP for rapid reversal.
What is 4-Factor PCC
400
A patient taking Dabigatran starts a 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 taking Warfarin for Atrial Fibrillation has the following weekly dosing schedule:
5 mg daily except 2.5 mg on Sundays
Their INR today is 1.5, and the goal INR is 2–3.
Guidelines recommend increasing the total weekly dose by 10–15% for a subtherapeutic INR.
Question:
What is the patient’s current total weekly dose, and what new weekly dose range should be considered?
What is
Current weekly dose: 32.5 mg/week
New recommended weekly dose range: ~35.8–37.4 mg/week
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 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
A patient on Rivaroxaban presents with life-threatening gastrointestinal bleeding within 2 hours of their last dose. In addition to reversal strategies, what non-antidote intervention may reduce further drug absorption?
What is activated charcoal?
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 (≈55% decrease)
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