PSA Cardiovascular Prescribing 3

Question 1

A 75-year-old woman with non-valvular AF and a CHA₂DS₂-VASc score of 4 requires anticoagulation. Which agent is most appropriate as first-line therapy?

Accepted Answer

Apixaban 5mg twice daily

Answer

DOACs such as apixaban are recommended over warfarin for non-valvular AF due to superior efficacy and safety; antiplatelet therapy is not an acceptable alternative.

Question 2

A 68-year-old man with AF and CKD (eGFR 25 mL/min) needs anticoagulation. Which DOAC is most problematic at this level of renal impairment?

Accepted Answer

Dabigatran

Answer

Dabigatran is approximately 80% renally eliminated and is contraindicated when eGFR < 30 mL/min, making it the most problematic DOAC in severe CKD.

Question 3

A patient on warfarin for AF presents with an INR of 8.5 and no active bleeding. What is the most appropriate initial management?

Accepted Answer

Withhold warfarin, give oral vitamin K 1–2.5mg, and recheck INR in 24 hours

Answer

For markedly elevated INR (>8) without active bleeding, withholding warfarin and administering low-dose oral vitamin K 1–2.5mg is the appropriate management.

Question 4

A 78-year-old man on apixaban 5mg twice daily for AF has his medication reviewed. His weight is 58kg and serum creatinine is 140 µmol/L. What dose adjustment is required?

Accepted Answer

Reduce to 2.5mg twice daily based on two criteria being met

Answer

Apixaban dose should be reduced to 2.5mg twice daily when at least 2 of 3 criteria are met: age ≥80, weight ≤60kg, or creatinine ≥133 µmol/L; this patient meets weight and creatinine criteria.

Question 5

A patient with AF on rivaroxaban 20mg daily requires an elective colonoscopy with low bleeding risk. When should rivaroxaban be withheld?

Accepted Answer

24 hours before the procedure

Answer

For procedures with low bleeding risk, rivaroxaban should be withheld for 24 hours (one dose missed) prior to the procedure given its half-life of 5–9 hours.

(PSA) Prescribing Safety Assessment Practice Test

(PSA) Prescribing Safety Assessment Practice Test

PSA Cardiovascular Prescribing 3