[Fundamental and clinical studies on cefixime in pediatrics]

Bacteriological, pharmacokinetic, and clinical studies of cefixime (CFIX), a newly developed oral cephalosporin, was conducted in our pediatric department as outlined below. Bacteriology The prevalent MICs of CFIX by microbiological species, compared with those of the reference drugs, were detailed below. Against 16 strains of S. aureus, the MICs averaged 6.25 micrograms/ml, and were found to be nearly the same as the MICs of amoxicillin (AMPC) but higher than those of cephalexin (CEX) and cefaclor (CCL). For 4 strains of S. pyogenes, the MICs averaged 0.05 microgram/ml, and were higher than the MICs of AMPC but lower than those of CEX and CCL. Mean MICs of CFIX against other clinical isolates were lower than those of CEX, CCL, or AMPC; E. coli (20 strains), 3.13 micrograms/ml; K. pneumoniae (9), 0.10 microgram/ml; P. mirabilis (16), 0.025 microgram/ml; P. vulgaris (5), 0.10 microgram/ml; H. influenzae (11), 0.05 microgram/ml; and S. typhimurium (4), 0.10 microgram/ml. The MICs of CFIX against 10 strains of P. aeruginosa were distributed at and above 25 micrograms/ml, a range much lower than greater than or equal to 100 micrograms/ml for CEX, CCL, or AMPC. Pharmacokinetics The serum concentrations and urinary recovery were studied in 3 children ranging from age 7 to 13. They were given CFIX on empty stomach in 2 different single doses of 3 and 6 mg/kg in a cross-over design. Average serum CFIX concentrations were dose-dependent, as evidenced by the respective peak concentrations of 1.70 microgram/ml for a 3 mg/kg dosage and 2.72 micrograms/ml for 6 mg/kg, which were attained 4 hours after the administration of the drug. The average half-lives of CFIX in the serum were 3.09 hours and 3.11 hours, respectively, and the 12-hour serum concentrations were 0.32 microgram/ml and 0.77 microgram/ml, respectively, for the 2 different dose levels. The average 12-hour urinary recovery was 25.2% and 22.3%, respectively. Clinical study Clinical effectiveness, bacteriological effectiveness, and side effects were studied in 27 children with infection including 4 patients with acute pharyngitis, 13 with acute purulent tonsillitis, 5 with acute pneumonia, 3 with urinary tract infection, and 1 each with acute rhinitis and acute bronchitis. One child with acute pneumonia (Mycoplasma pneumonia) was excluded from the study. The therapeutic effectiveness was "excellent" in 21, "good" in 3, "fair" in 1, and "poor" in 1, with an effectiveness rate of 92.3%.(ABSTRACT TRUNCATED AT 400 WORDS)