Which factor increases the risk of nephrotoxicity with gentamicin?

Which factor increases the risk of nephrotoxicity with gentamicin?

• A. Preexisting renal impairment
• B. Young age
• C. Regular exercise
• D. Adequate hydration

Answer: (A)

Gentamicin nephrotoxicity is strongly linked to how long the drug stays in the kidneys. Since gentamicin is cleared by the kidneys, preexisting renal impairment reduces clearance, raises trough levels, and increases exposure of the renal proximal tubule cells to the drug. This higher exposure damages these cells and raises the risk of nephrotoxicity. Hydration helps protect by maintaining urine flow, while regular exercise has no direct effect. Very young patients can be more susceptible due to immature kidney function, but the most direct and consistent risk factor described here is existing renal impairment.

Gentamicin nephrotoxicity is strongly linked to how long the drug stays in the kidneys. Since gentamicin is cleared by the kidneys, preexisting renal impairment reduces clearance, raises trough levels, and increases exposure of the renal proximal tubule cells to the drug. This higher exposure damages these cells and raises the risk of nephrotoxicity. Hydration helps protect by maintaining urine flow, while regular exercise has no direct effect. Very young patients can be more susceptible due to immature kidney function, but the most direct and consistent risk factor described here is existing renal impairment.