Amikacin in obstetric, gynecologic, and neonatal infections: laboratory and clinical studies.

Based on the proportion of resistant, moderately sensitive, and sensitive strains, the descending order of activity of amikacin against clinical isolates of urinary pathogens was Salmonella, Klebsiella, Enterobacter, Escherichia coli, Staphylococcus aureus, Citrobacter, Proteus species, and Pseudomonas aeruginosa. However, amikacin was the most active of the antibiotics tested (including gentamicin and tobramycin) against 100 strains of P. aeruginosa. The calculated half-life of amikacin was substantially longer in patients with compromised renal function than in normal subjects. Immaturity of renal function, characteristic of the newborn, similarly slowed the rate of excretion of amikacin. The cure rate (complete clinical remission and eradication of the pathogen) was 91% in 22 patients with urinary tract infection (including 16 with chronic pyelonephritis) treated with 500 mg of amikacin every 8 or 12 hr for eight to 17 days. After single injections of 7.5 mg/kg 2-3 hr before delivery, appreciable amounts of the drug were recovered from the cord blood. No local or systemic intolerance or laboratory abnormalities were observed in a total of 42 patients (including eight infants) treated for a maximum of two weeks. No ototoxicity was demonstrable in any of the 12 patients subjected to audiometry; nystagmography revealed slight vestibular dysfunction in two elderly patients.