Effects of Cefixime and Cefaclor on Pharyngeal Flora in Children

Influences of cefixime and cefaclor, oral antibiotics, were studied in 50 children (age range, 11 months to 13 years) with pharyngitis. Daily doses of cefixime were 6 to 10 mg/kg in 25 children and those of cefaclor were 40 to 50 mg/kg in 25 children. Pharyngeal swabs were taken before and after 3 to 7 days of the antibiotic treatment. Pathogenic organisms, such as Streptococcus pyogenes, Haemophilus influenzae and Streptococcus pneumoniae, were isolated in 14 children before and in 1 child after cefixime use. But these bacteria were isolated in 15 children before and in 9 children, and 3 strains of H. influenzae and 3 strains of S. pneumoniae were newly isolated after cefaclor use. An isolation rate of Gram-negative bacilli, such as Acinetobacter spp., were increased after use of cefixime. In both antibiotics, isolation rates of yeasts were slightly increased. An isolation rate of alpha-hemolytic streptococci was increased from 16% to 48% by cefixime treatment and from 24% to 52% by cefaclor treatment. The MIC50 of cefixime and cefaclor against alpha-hemolytic streptococci isolated after treatment was higher than that isolated before. Effects of cefixime and cefaclor was less extensive than that of ampicillin in previous reports.