A nurse is caring for a client who has a prescription for 81 mg acetylsalicylic acid (Aspirin) daily. Which of the following actions should the nurse plan to take?

Choice A rationale Aspirin (acetylsalicylic acid) at a low daily dose of 81 mg is typically used for its antiplatelet effects (irreversible inhibition of COX-1 in platelets) to prevent cardiovascular events. This dose has minimal analgesic or anti-inflammatory effects. Therefore, monitoring a pain rating of 6 or more is not a primary concern for this specific prophylactic indication. Choice B rationale Encouraging increased intake of green leafy vegetables, which are rich in Vitamin K, is relevant for clients on warfarin (Coumadin), as Vitamin K can counteract its effect. Aspirin, however, works on platelet aggregation and is not affected by dietary Vitamin K levels. This advice is irrelevant to the pharmacodynamics of aspirin. Choice C rationale Aspirin is a non-steroidal anti-inflammatory drug (NSAID) that can cause gastrointestinal irritation and bleeding, a side effect that is dose-dependent but still possible with low-dose therapy. Black, tarry stools (melena) are an indication of upper gastrointestinal bleeding due to the degradation of hemoglobin to hematin. The nurse must monitor for this serious adverse effect. Choice D rationale Aspirin, especially at higher doses, can impair renal function by inhibiting prostaglandin synthesis, which is essential for maintaining renal blood flow. This effect typically leads to an increase (not a sudden drop) in blood urea nitrogen (BUN) (normal range 8-20 mg/dL) and creatinine (normal range 0.6-1.2 mg/dL) levels due to decreased glomerular filtration.