Because of increased
aminoglycoside resistance of hospital bacterial isolates,
aminoglycoside sensitivity patterns of isolates in a large children's hospital were assessed before and during a 33-month period of almost exclusive
amikacin use. There was no significant change in overall resistance rates of gram-negative enteric bacteria to
gentamicin (4.8 percent and 4.6 percent),
tobramycin (2.5 percent and 3.6 percent), and
amikacin (1.2 percent and 1.8 percent) from the pre-
amikacin period to the
amikacin usage period, respectively. No significant differences were observed for isolates of Escherichia coli, Klebsiella, Serratia, Acinetobacter, and Pseudomonas species. In contrast, significant decreases in
gentamicin and
tobramycin resistance rates for Enterobacter, Citrobacter, and Pseudomonas aeruginosa and in
gentamicin resistance of Proteus were found. Very little change in resistance of staphylococcal isolates was seen during a shorter evaluation period. Pediatric
aminoglycoside usage includes
therapy of neonatal
infections,
cystic fibrosis, febrile neutropenic episodes in patients with
cancer, abdominal surgery,
bacterial endocarditis, and gram-negative
central nervous system infections.
Amikacin has also been used successfully as single-dose
therapy of
urinary tract infections, and acceptable cerebrospinal fluid levels of
amikacin have been documented in hydrocephalic patients with ventriculitis. In vitro studies of 22 bacterial isolates demonstrated synergy between
amikacin and
penicillin or newer
cephalosporins in 13, an additive effect in seven and indifference in two. No antagonism was found. In addition, in vivo synergy between
imipenem and
amikacin was found in neutropenic infant rats with P. aeruginosa
sepsis using a strain with which no synergy was demonstrable in vitro.
Amikacin is effective in pediatric
infections and is well tolerated by children. Because excessive or inadequate levels are frequent with usually recommended doses, particularly in neonates and patients with compromised renal function or
cystic fibrosis, serum levels should be monitored to minimize risk and to ensure therapeutic levels.