NCLEX-PN® ExaminationSafety and Infection ControlHard
An LPN is reinforcing teaching with a client who is prescribed warfarin. The client states, 'I always take St. John's wort for my depression.' Which instruction should the LPN provide?
- ADiscontinue St. John's wort immediately and report to the provider.
- BContinue taking St. John's wort as it does not interact with warfarin.
- CIncrease your intake of leafy green vegetables to counteract the interaction.
- DTake St. John's wort at least 4 hours apart from warfarin.
Show answer & explanationAnswer & explanation
Correct answer: A. Discontinue St. John's wort immediately and report to the provider.
St. John's wort is a known inducer of cytochrome P450 enzymes, which can decrease the effectiveness of warfarin, leading to an increased risk of blood clots. The client should discontinue it immediately and inform their healthcare provider to adjust the warfarin dosage if necessary.
Why the other options are wrong
- B. This statement is incorrect; St. John's wort has significant interactions with warfarin.
- C. Increasing vitamin K-rich foods (leafy greens) would further counteract warfarin's effects, which is dangerous in this scenario.
- D. Separating administration times does not mitigate the enzyme-inducing effect of St. John's wort.
Warfarin and Herbal Interactions
Warfarin is an anticoagulant that has numerous significant interactions with herbal supplements, which can either increase or decrease its anticoagulant effect, leading to serious adverse events.
- Many herbals (e.g., St. John's wort, ginseng, ginkgo, garlic) interact with warfarin.
- Interactions can alter the International Normalized Ratio (INR).
- Clients should always inform their provider about all supplements they are taking.
Memory trick: Warfarin's Weakened by Wild Herbs