A nurse is preparing to administer vancomycin IV to an adult client. The client asks the nurse if the medication can be given 2 hr earlier. Which of the following statements should the nurse make?

A. The nurse cannot adjust IV antibiotic schedules solely for convenience, as consistent timing is necessary to maintain therapeutic drug levels. B. Infusing vancomycin at a faster rate is unsafe and increases the risk of complications such as red man syndrome. C. This is incorrect because the 2-hour administration window applies to non–time-critical medications. IV antibiotics like vancomycin are time-critical and must be given within 30 minutes of the scheduled time. D. Time-critical medications, such as IV antibiotics, must be administered within 30 minutes before or after the scheduled time, making this the most accurate response.