High dosage tobramycin treatment of children with cystic fibrosis. Bacteriological effect and clinical ototoxicity.

The bacteriological effect of chemotherapy against mucoid strains of Pseudominas aeruginosa in the lower respiratory tract of patients with cystic fibrosis is reported. A comparison of the effect of high doses of tobramycin (10 mg/kg/24 h) given alone or in combination with carbenicillin showed a significant difference in favour of the combination therapy. In 74.5% of the initially successful courses the patients were recolonized within one month. Fifty-three patients were examined by audiometric and vestibular tests. Only in one patient was it possible to register a transient, high tone hearing impairment at 8000 Hz bilaterally, that might be attributed to the tobramycin treatment. It is concluded that high dose tobramycin treatment in children and adolescents with normal kidney function implies only a minimal clinical risk of adverse ototoxic effects, even after repeated courses of treatment. No nephrotoxic side-effects were found in this material.