A nurse is reviewing the laboratory results of a client who has atrial fibrillation and a prescription for warfarin. After informing the provider that the INR is 2.5, the nurse should expect which of the following prescriptions?

Choice A Reason:
Levothyroxine 100 mcg PO every morning is incorrect. Indicates the dosage (100 mcg) and the route (by mouth) to be taken every morning.
Choice B Reason:
Simvastatin 40 mg PO at bedtime: Specifies the dosage (40 mg) and the timing (at bedtime) for administration.
Choice C Reason:
Acetaminophen 500 mg every 4 hr RN for fever is correct. The term "RN" in this context might be interpreted as "right now" rather than the intended meaning, which could cause confusion regarding the frequency of acetaminophen administration. The nurse should seek clarification to ensure accurate and safe dosing instructions.
Choice D Reason:
Morphine 4 mg IV every 4 hr PRN for pain: Specifies the dosage (4 mg), the route (intravenous), and the frequency (every 4 hours as needed) for pain management.

Choice A Reason:
INR (International Normalized Ratio) is incorrect. INR is a measurement used to monitor the effects of anticoagulants like warfarin. It assesses the blood's ability to clot. Filgrastim does not directly affect INR levels, so monitoring INR would not provide information about the effectiveness of filgrastim in stimulating white blood cell production.
Choice B Reason:
BUN (Blood Urea Nitrogen) is incorrect. BUN levels primarily indicate kidney function and hydration status. They are not directly influenced by filgrastim treatment. Monitoring BUN is essential for assessing kidney function but does not reflect the effectiveness of filgrastim therapy in increasing white blood cell counts.
Choice C Reason:
WBC count is correct. Filgrastim is a medication that stimulates the production of white blood cells (WBCs), particularly neutrophils. Therefore, the key laboratory value to monitor for assessing the effectiveness of filgrastim therapy is the WBC count. An increase in the WBC count, particularly in the neutrophil count, signifies the intended therapeutic effect of filgrastim in boosting the immune system's response by increasing the production of these infection-fighting cells.
Choice D Reason:
Potassium level is incorrect. Potassium levels are crucial for heart and muscle function. While certain medications might affect potassium levels, filgrastim's primary action is on stimulating white blood cell production and does not directly impact potassium levels. Monitoring potassium levels is essential for overall health but does not specifically indicate the effectiveness of filgrastim treatment.