Preliminary clinical trial with amikacin in chronic recurrent gram-negative bacterial infections refractory to other antimicrobial agents.

Eleven patients with 16 infections due to Enterobacteriaceae or Pseudomonas that were in most cases refractory to treatment with cephalosporins, kanamycin, gentamicin, tobramycin, carbenicillin, or ampicillin (administered singly or in combinations) received 1 g of amikacin daily by the intramuscular route (10 patients) or 0.4 g daily (one patient with renal insufficiency). The average duration of treatment was eight days. At the beginning of treatment, 18 pathogens were sensitive to amikacin at concentrations of 0.25-2 mug/ml. Of the 16 infections, 10 were cured clinically. Thirteen of the 19 pathogens isolated initially were eradicated, and five persisted during treatment but without change in in vitro sensitivity. A strain of Pseudomonas cepacia recovered from a diabetic patient and sensitive initially to 8 mug of amikacin/ml showed an eightfold increase in minimal inhibitory concentration. Superinfection with P. cepacia resistant to amikacin was noted in one case and urinary colonization with Candida albicans in another. No abnormalities of hematopoietic, hepatic, or renal function were observed in laboratory tests.