A nurse is caring for a client who has a fungal infection and has a new prescription for amphotericin B. Which of the following laboratory values should the nurse report to the provider before initiating the medication?

A. Sodium 140 mEq/L: This value is within the normal reference range (135–145 mEq/L). Sodium balance is important to monitor with many medications, but this finding does not pose a contraindication to initiating amphotericin B. B. BUN 55 mg/dL: This value is significantly elevated above the normal range (10–20 mg/dL). Amphotericin B is nephrotoxic, and impaired renal function increases the risk of severe kidney injury. This abnormal result must be reported before administering the drug. C. Glucose 120 mg/dL: Although slightly above fasting normal levels, this value is not dangerously high and does not impact the safe initiation of amphotericin B. Glucose is not a critical concern in relation to this antifungal medication. D. Potassium 4.5 mEq/L: This value is within the normal range (3.5–5.0 mEq/L). While amphotericin B can cause hypokalemia, a normal potassium level at baseline does not require withholding the drug.