Nephrotoxicity of Common Drugs Used in Clinical Practice

To the Editor.  —We read with interest the article by Cooper and Bennett, on drug-induced nephrotoxicity, which appeared in the July 1987 issue of the Archives.¹ The authors should be commended on the excellent and thoroughly detailed review of this complex subject, in particular, the explanation regarding aminoglycoside-induced renal dysfunction. Although dosing recommendations were a minor portion of the article, there are a few areas regarding aminoglycoside dosing that we would like to address.The authors' recommended maintenance dose of aminoglycosides (1.0 mg/kg of body weight [approximately 3.0 mg/kg/d]) may not be sufficient to produce "therapeutic" peak serum concentrations, especially in critically ill patients and patients with respiratory infections. A study by Zaske et al² demonstrated an average maintenance dose requirement of 4.5 mg/kg/d of gentamicin to obtain peaks of 6.9 μg/mL. Peak gentamicin/ tobramycin concentrations of greater than 4.0 to 5.0 μg/mL achieved early in therapy have