A clinical study on the ototoxic effects of tobramycin

In a clinical, prospective, non-randomized study, tobramycin has shown its high antibacterial activity in Gram-negative bacillary infections. The incidence of ototoxic side effects was very low: none of 18 patients studied before, at the end and 9 months after completion of tobramycin therapy showed any change in pure tone audiograms. Five of these 18 patients had renal impairment: 3 of them developed subjective and objective evidence of vestibular dysfunction, as demonstrated by caloric vestibulometry. However, these bilateral vestibular lesions all proved to be reversible a few weeks after cessation of therapy. Despite the low incidence and the reversibility of the ototoxic side effects, it seems advisable to monitor patients on long-duration tobramycin therapy for signs of vestibular dysfunction, particularly in cases of renal insufficiency.