[Bacteriological, pharmacokinetic and clinical studies on a rokitamycin dry syrup in the pediatric field]

Bacteriological, pharmacokinetic and clinical studies were done on the effect of rokitamycin (RKM, TMS-19-Q) in the field of pediatrics. The results are summarized below. 1. Antibacterial activities Antibacterial activities of RKM against Staphylococcus aureus (including 50 methicillin-sensitive and 50 methicillin-resistant strains), 18 strains of Haemophilus influenzae and 50 strains of Campylobacter jejuni were studied comparatively with activities of josamycin (JM), midecamycin (MDM), erythromycin (EM) and cefaclor (CCL) or ampicillin. Minimum inhibitory concentrations (MICs) of the 5 antibiotics against methicillin-sensitive S. aureus showed a wide variation but RKM was somewhat superior among them. MIC80 of those antibiotics tested against methicillin-sensitive S. aureus were as follows; RKM 1.56, JM 12.5, MDM 12.5, EM 6.25, and CCL 3.13 micrograms/ml. Among methicillin-resistant S. aureus (MRSA), ratios of strains highly resistant to these antibiotics (MIC greater than or equal to 100 micrograms/ml) to total number of strains tested were: 18% to RKM, and 26%, 34% and 48% to JM, MDM and EM, respectively, again showing the superiority of RKM and the proliferation of resistant organisms to EM. MICs of RKM against H. influenzae were distributed in a range between 0.78 and 12.5 micrograms/ml, which were similar to MIC range of CCL, and approximately twice as high as that of EM, but 4 folds lower than those of JM and MDM. Against C. jejuni, the MIC range of RKM was quite broad, 0.10-12.5 micrograms/ml, with a peak value of 0.20 micrograms/ml. The cumulative number of strains vs. MIC curve was similar to that of EM, and RKM was approximately 4 to 8 folds more effective than the other 3 antibiotics. 2. Absorption and excretion The absorption and the excretion of RKM were studied with its dry syrup preparations. Dose levels examined were 5 mg/kg in 2 cases, 10 mg/kg in 7 cases, 15 mg/kg in 2 cases and 20 mg/kg in 1 case. Peak concentrations of RKM in blood were not dose-dependent and were 0.16-0.23, 0.29-0.91, 0.35-0.46 microgram/ml and 0.53 microgram/ml, respectively, for the 4 dose levels. Most of drug levels dropped below the detection limit in 4 hours after the administration when dose levels up to 10 mg/kg were used, and when dose levels were at or above 15 mg/kg, 0.07-0.09 microgram/ml of RKM was detected in blood at 6 hours after the administration. Urinary recovery rates in 6 hours were between 0.19 and 3.31%.(ABSTRACT TRUNCATED AT 400 WORDS)