What monitoring is recommended during gentamicin therapy to minimize toxicity?

• A. Renal function tests and trough/peak levels
• B. Liver function tests only
• C. Blood pressure readings only
• D. Complete blood count only

Answer: (A)

Gentamicin has a narrow therapeutic window and can cause nephrotoxicity and ototoxicity, so monitoring focuses on both how the drug behaves in the body and how much of it is in the blood. Renal function tests (such as serum creatinine and estimated creatinine clearance) help detect early kidney injury, which is a common and serious toxicity with this drug. At the same time, therapeutic drug monitoring of trough and peak levels ensures the drug exposure stays within the safe and effective range: the trough is drawn just before the next dose to ensure levels aren’t accumulating too much, while the peak is drawn after dosing to confirm the concentration is high enough to be effective but not so high that toxicity risk rises. If troughs are too high, dosing intervals can be lengthened or doses reduced; if peaks are too high, the dose can be lowered. Liver function tests or basic CBC alone don’t specifically monitor the main toxicity risks of gentamicin, so they aren’t the primary tools for minimising toxicity.