A client is receiving intravenous (IV) vancomycin and the nurse plans to draw blood for a peak and trough to determine the serum level of the medication. Which of the following collection times provide the best determination of these levels?

Choice A reason: This is not the correct time to collect the peak and trough levels. The peak level should be measured after the completion of the IV dose, not during the administration. The trough level should be measured just before the next administration, not 30 minutes before. Choice B reason: This is the correct time to collect the peak and trough levels. The peak level should be measured one hour after the completion of the IV dose, when the concentration of the medication is highest in the blood. The trough level should be measured one hour before the next administration, when the concentration of the medication is lowest in the blood. Choice C reason: This is not the correct time to collect the peak and trough levels. The peak level should be measured one hour after the completion of the IV dose, not two hours after. The trough level should be measured one hour before the next administration, not two hours before. Choice D reason: This is not the correct time to collect the peak and trough levels. The peak level should be measured one hour after the completion of the IV dose, not immediately after. The trough level should be measured one hour before the next administration, not 30 minutes before.