Tobi (tobramycin) has been approved as an inhaled antibiotic for the treatment of cystic fibrosis. It is indicated to treat Pseudomonas aeruginose infections, a common cause of lung infections in cystic fibrosis patients. The drug has been available intravenously since 1975.
Clinical trials demonstrated an increase in patients' lung function to be as much as 11% during six months of treatment. Of the approximate 500 patients studied, hospital admission were reduced by 26% and stays averaged 5.1 days for Tobi patients compared with 8.1 for placebo patients.
The main side effects were hoarseness and tinnitus. Eight Tobi patients had 16 episodes of tinnitus, while there were none in the placebo group. There was no evidence of hearing loss, but the FDA cautioned that tinnitus could be a preliminary indication of drug-related ototoxicity.