A client on vancomycin should be monitored for signs of renal toxicity. Which of the following indicates such toxicity?

A client on vancomycin should be monitored for signs of renal toxicity. Which of the following indicates such toxicity?

• A. Intermittent flank pain
• B. Increased serum creatinine level
• C. Increased blood pressure
• D. Decreased BUN level

Answer: (B)

Vancomycin can cause kidney injury, so the clearest signal is a rise in serum creatinine. Creatinine is a waste product removed by the kidneys; when kidney function declines (lower GFR), creatinine builds up in the blood. So an increasing creatinine level directly indicates nephrotoxicity and prompts dose adjustments or closer monitoring. The other options don’t reliably indicate drug-induced kidney injury: intermittent flank pain can come from stones or other causes and isn’t specific for toxicity; higher blood pressure isn’t a specific early sign of nephrotoxicity; and a decreased BUN isn’t a typical or reliable marker of kidney injury and can be influenced by factors like hydration and protein intake.

Vancomycin can cause kidney injury, so the clearest signal is a rise in serum creatinine. Creatinine is a waste product removed by the kidneys; when kidney function declines (lower GFR), creatinine builds up in the blood. So an increasing creatinine level directly indicates nephrotoxicity and prompts dose adjustments or closer monitoring.

The other options don’t reliably indicate drug-induced kidney injury: intermittent flank pain can come from stones or other causes and isn’t specific for toxicity; higher blood pressure isn’t a specific early sign of nephrotoxicity; and a decreased BUN isn’t a typical or reliable marker of kidney injury and can be influenced by factors like hydration and protein intake.