Drug toxicity serum gentamicin

Severe nephrotoxicity has been reported in three renal transplant patients who received ciclosporin and gentamicin, and in others receiving both drugs before surgical procedures, even though toxic serum concentrations of either drug were not reached (231). 

In fact elderly people have a reduced creatinine clearance, often balanced by the decline in creatinine input with a resulting normal serum creatinine. This is clinically important because drugs which are cleared through the kidneys need to be given in scaled down amounts to prevent cumulation and possible toxicity - e.g., gentamicin and other parenteral aminoglycosides, digoxin. 

In a survey of aminoglycoside treatment in 2022 patients in Saudi Arabia, 8.8%, 18%, and 12% had trough concentrations considered toxic for amikacin, gentamicin, and tobramycin respectively, whereas there were peak serum drug concentrations in the subtherapeutic range in 53%, 50%, and 57% respectively (197). Toxic concentrations were noticed mainly in patients aged over 60 years and in patients in the intensive care unit, coronary care unit, and burn unit. 

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