Clinical evaluation of aminoglycoside toxicity: tobramycin versus gentamicin, a preliminary report

Abstract

A prospective evaluation of 68 courses of therapy in 60 patients receiving intravenous tobramycin or gentamicin, was performed to determine the incidence of ototoxicity. Pure-tone and speech audiograms and electronystagmograms were performed prior to or within 48 h of onset of drug and periodically thereafter. There were 28 patient-episodes (6 of 23 on tobramycin and 22 of 45 on gentamicin) during which ototoxicity and/or nephrotoxicity developed. The preliminary data suggest that tobramycin may be less toxic than gentamicin although direct comparisons are difficult. Among the significant variables apparently associated with toxicity are total dosage, area under the curve, and initial serum creatinine. The need for baseline audiograms is stressed