A nurse is preparing to administer vancomycin 15 mg/kg/day divided equally every 12 hr. The client weighs 198 lb. How many mg should the nurse administer with dose? (Round the answer to the nearest whole number. Use leading zero if it applies. Do not use a trailing zero.)

To calculate the dose of vancomycin for the client weighing 198 lb, first convert lb to kg (1 kg = 2.2 lb). Client weight = 198 lb / 2.2 = 90 kg. Next, calculate the total daily dose: 15 mg/kg/day x 90 kg = 1350 mg/day. Since the dose is divided equally every 12 hours, administer 675 mg every 12 hours. Rounded to the nearest whole number, each dose will be 668 mg. Therefore, the correct answer is 668 mg. Other choices are incorrect as they do not follow the correct calculation process or do not account for the weight conversion and dosage frequency.