[Laboratory and clinical studies on norfloxacin in the pediatric field].

In bacteriological, pharmacokinetic and clinical studies on norfloxacin (NFLX, AM-715), the following results were obtained: 1. Antibacterial activity of NFLX, nalidixic acid (NA), amoxicillin (AMPC), cefaclor (CCL), erythromycin (EM) and fosfomycin (FOM) against clinically isolated bacteria was examined, and it was found that MIC80 of NFLX against Staphylococcus aureus was 3.13 micrograms/ml, thus NFLX exhibited stronger antimicrobial activity than NA, AMPC, CCL, EM and FOM. NFLX also showed good activities to those strains of S. aureus which were resistance to NA, AMPC, CCL, EM and FOM. 2. MIC80 of NFLX against Escherichia coli was 0.05 micrograms/ml or lower, thus NFLX showed better activity than NA, AMPC, CCL, EM and FOM. 3. In single oral administration at fasting of NFLX at dose levels of 1.5-2.4 and 2.5-3.4 mg/kg in tablet form mean peak values of serum concentration were 0.32 micrograms/ml reached in 1 hour and 0.38 micrograms/ml in 2 hours, T1/2's obtained were 1.7-4.0 and 2.2-2.9 hours and AUC's were 1.54 +/- 0.52 and 2.02 +/- 0.93 micrograms.hr/ml, respectively. Urinary recovery rates of 11.6-46.9%, 13.8-35.4% in 6-8 hours were demonstrated with the 2 ranges of dose levels, respectively. 4. NFLX was administrated to 34 patients consisting of 8 cases of acute pneumonia, 3 cases of acute tonsillitis, 3 cases of bacterial colitis, 19 cases of urinary tract infections and 1 case of purulent parotitis. The clinical efficacy rate was 97.1% including 34 cases with excellent results in 28, good in 5 and fair in 1. 5. The bacterial eradication rate was 96.8% (30/31) with one exception of a Campylobacter jejuni strain. 6. NFLX was given to patients according to a dosing regimen with 4.5-21.4 mg/kg/day dose levels for 3 doses daily except 1 case of UTI where 2 daily doses were given daily. 7. No adverse reactions were observed. Abnormal laboratory test value was obtained in 1 case where eosinophilia was found. The above results have suggested that NFLX is a useful and safe antimicrobial agent against bacterial infections in children.