Amikacin therapy of exacerbations of Pseudomonas aeruginosa infections in patients with cystic fibrosis.

Amikacin, a new semisynthetic aminoglycoside antibiotic with activity against Pseudomonas aeruginosa, was used to treat 22 acute exacerbations of chronic pulmonary infections in 18 patients with cystic fibrosis. Patients ranged from 5 to 32 years of age and had mucoid P. aeruginosa isolated from sputum. The amikacin dose was usually 7.5 mg/kg every eight hours but was increased to 10 mg/kg and/or carbenicillin was added in selected cases depending on clinical course. Although P. aeruginosa was not eliminated from our patients' sputum except in two cases, there was a good clinical response in 19 of 22 courses. Significant improvement in chest x-ray films, spirometry, or arterial oxygen tension was documented in 11 of 17 courses. One instance of serum creatinine level elevation could not be attributed to this antibiotic. Two patients showed minimal (15 dB) unilateral high-frequency hearing loss on serial audiograms. Activity against many gentamicin-resistant strains and high blood levels are among the attractive properties of amikacin. Amikacin is clinically effective in treating Pseudomonas-associated pulmonary infections complicating cystic fibrosis.