A 3-month-old infant is being treated with Vancomycin for bacterial meningitis. Order: 60mg/kg/day divided every 6 hours. The infant weighs 11 pounds. The nurse first confirms safe dose. The nurse then calculates the dosage. Which one of the following is the correct SINGLE dose order for the nurse to administer?

The correct answer is A: 75 mg. To calculate the correct dose, first convert the infant's weight from pounds to kilograms by dividing by 2.2 (11 lb / 2.2 = 5 kg). Then, multiply the weight by the ordered dose (60 mg/kg/day) to find the daily dose (5 kg * 60 mg/kg = 300 mg/day). Next, divide the daily dose by the number of doses per day (every 6 hours = 4 doses/day) to find the single dose (300 mg/day / 4 doses = 75 mg). Choice B is incorrect because it doesn't account for the weight-based dosing. Choice C is incorrect as it is the ordered dose without considering the weight. Choice D is incorrect as it is too high, exceeding the calculated dose for the infant's weight.