Tobramycin ototoxicity. Repeated courses of high dosage treatment in children with cystic fibrosis.

Fifty-three patients with cystic fibrosis were treated with large doses of tobramycin 
sulphate, 10 mg/kg/24 h. Patients received an average of 3.2 courses, 
each lasting 10 to 14 days. The patients were examined with 
audiometric and vestibular tests, and in one patient, a 10-year-old girl, 
we found a transient high tone loss at 8000 Hz bilaterally 
that might be attributed to the tobramycin treatment. All patients had 
normal kidney function. High dose tobramycin treatment in children with normal 
kidney function gives minimal clinical risks of adverse ototoxic effects, even 
after repeated courses of treatment. 