skip to main content

St John's wort and DOAC — GPhC CRA MCQ

Instant feedback + full explanation. One question, done properly.

ModerateDrug InteractionsSt John's wort and DOACGPhC CRA

A 39-year-old woman taking apixaban asks to buy St John's wort for low mood. She has no bleeding symptoms and takes apixaban for a previous pulmonary embolism. What is the most important interaction to flag?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — St John's wort can reduce apixaban exposure and anticoagulant effect

St John's wort induces drug-metabolising enzymes and transporters and can reduce exposure to some anticoagulants, including DOACs. Reduced anticoagulant effect could increase thrombosis risk. The patient should be advised not to use it and to discuss mood symptoms with a healthcare professional.

Reference: BNF