A nurse is providing teaching to a client who has a new prescription for warfarin. Which of the following instructions should the nurse include in the teaching?

Rationale: A. “Use an electric razor when shaving while taking this medication.” Warfarin increases bleeding risk by inhibiting vitamin K–dependent clotting factors. Using an electric razor reduces the chance of cuts and bleeding during shaving, making this a critical safety teaching point. B. “This medication can cause back pain” Back pain is not a common or expected side effect of warfarin. If a client on warfarin experiences unexplained back pain, it should be evaluated as it could indicate internal bleeding, but it is not typical enough to be part of routine teaching. C. "Take the last dose of the day 1 hour before bedtime” Warfarin is usually taken once daily, preferably at the same time, but timing in relation to bedtime is not required. The key is consistency and regular INR monitoring to guide dosing. D. “Avoid taking the medication with milk products” Unlike some antibiotics, warfarin’s absorption is not significantly affected by dairy. Dietary consistency with vitamin K is more important than avoiding milk, and milk products are not contraindicated.