A client is receiving intravenous vancomycin, and the nurse plans to draw blood for a peak and trough to determine the serum level of the drug. Which collection times would provide the best determination of these levels?

The correct answer is D. Immediately after completion of the IV dose and 30 minutes before the next administration of the medication. Explanation: Peak levels measure the highest concentration of the drug in the bloodstream and should be drawn immediately after the IV infusion is completed. Trough levels measure the lowest concentration of the drug and should be drawn 30 minutes before the next scheduled dose. This helps ensure the drug remains within therapeutic levels and prevents toxicity. Why the other options are incorrect: A. One hour after completion of the IV dose and one hour before the next administration – Waiting one hour for the peak level is too long and may lead to an inaccurate measurement. B. Two hours after completion of the IV dose and two hours before the next administration – Waiting two hours for both peak and trough levels is too late for effective monitoring. C. Thirty minutes into the administration of the IV dose and 30 minutes before the next administration – The sample drawn mid-infusion does not represent peak levels, making this method ineffective. Key takeaway: Proper timing of vancomycin peak and trough monitoring ensures therapeutic drug levels while minimizing nephrotoxicity and ototoxicity.