A nurse is caring for an infant who has otitis media and is to receive amoxicillin 30 mg/kg/day in divided doses every 12 hr. The child weighs 13 lb. How many mg should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)

Convert the infant's weight from pounds (lb) to kilograms (kg). Patient weight (kg) = 13 lb / 2.2 lb/kg = 5.909 kg. Calculate the total daily dose in milligrams (mg). Total daily dose (mg) = Patient weight (kg) x Ordered dose (mg/kg/day) = 5.909 kg x 30 mg/kg/day = 177.27 mg. Calculate the single dose in milligrams (mg) for a single administration. Number of doses per day = 24 hours / 12 hours = 2 doses. Single dose (mg) = Total daily dose (mg) / Number of doses per day = 177.27 mg / 2 doses = 88.63 mg. Round to the nearest whole number = 89 mg.