Question

A 64-year-old man on warfarin (target INR 2.5) for AF is prescribed trimethoprim for UTI. Which is the safest immediate action regarding his anticoagulation?

Accepted Answer

Arrange earlier INR check within 3-5 days and advise monitoring

Answer

Stop warfarin for duration of antibiotics

Answer

Halve the warfarin dose empirically

Answer

Switch trimethoprim to ciprofloxacin

Answer

No change required

Practice question

A 64-year-old man on warfarin (target INR 2.5) for AF is prescribed trimethoprim for UTI. Which is the safest immediate action regarding his anticoagulation?