Assessment of potential ototoxicity following high-dose nebulized tobramycin in patients with cystic fibrosis.

A deterioration in pulmonary function is a common problem in patients with cystic fibrosis. One strategy which might help to arrest this process is the administration of aminoglycosides by nebulizer in dosages which greatly exceed those which are normally given parenterally. Ten patients (4-19 years of age) with cystic fibrosis underwent evoked response audiometry at regular intervals following a 400 mg dose of nebulized tobramycin; the concentrations of tobramycin in samples of blood taken at the same time intervals were also determined. No significant abnormalities in the audiometric investigations were detected. The relationship between shifts in vestibulocochlear potentials and long-term ototoxic sequelae in patients receiving aminoglycosides via a nebulizer requires further evaluation.