The nurse should instruct the client to avoid eating large amounts of leafy, green vegetables because they contain vitamin K. Vitamin K reduces the effects of warfarin. If a dose of warfarin is missed, the client should notify the healthcare provider and take the dose as soon as possible on the same day; the client should not double the dose the next day. The risk for bleeding may be higher if a nonsteroidal anti-inflammatory drug (not acetaminophen) is taken in combination with warfarin. If therapy is discontinued, the effects of warfarin may persist for 2 to 5 days.