A nurse is preparing to administer an IV infusion of metoprolol prescribed at 0.052 mg/kg/hr for a client weighing 64.5 kg. The medication is available in a concentration of 0.2 mg/mL. The infusion pump can only be programmed to whole numbers. What is the safest and most accurate infusion rate the nurse should program on the pump?

Brief Introduction: Metoprolol is a selective β1-adrenergic antagonist used to manage hypertension, tachyarrhythmias, angina, and heart failure. Intravenous administration requires accurate weight-based calculations, appropriate dose conversion, and safe infusion-rate adjustments to prevent hemodynamic instability and medication errors. Rationale: A. The prescribed dose is 0.052 mg/kg/hr × 64.5 kg = 3.354 mg/hr. Using a concentration of 0.2 mg/mL, the infusion rate equals 16.77 mL/hr. Because the pump accepts only whole numbers, programming 16.7 mL/hr is impossible. Therefore, this is not the correct administration rate. B. The calculated infusion rate is 16.77 mL/hr after converting the prescribed dose using the available concentration. Standard medication administration principles require rounding to the nearest whole number when pump limitations exist. Rounding down to 16 mL/hr unnecessarily decreases the prescribed therapeutic dose. Therefore, this option is inaccurate. C. The prescribed dose calculates to 3.354 mg/hr, which corresponds to 16.77 mL/hr using the available concentration. Since the infusion pump only accepts whole numbers, the rate should be rounded according to standard mathematical rules. Therefore, 17 mL/hr is the safest and most accurate rate. D. Converting the infusion to 1 mL/min would deliver 60 mL/hr, greatly exceeding the prescribed rate. Such a change would result in substantial overdosing and increase the risk of adverse cardiovascular effects. Infusion rates must reflect calculated medication requirements. Therefore, this is an unsafe calculation.