[Laboratory and clinical studies on clarithromycin in pediatrics]

Clarithromycin (TE-031, A-56268) is a new 14-membered ring macrolide antibiotic developed by Taisho Pharmaceutical Co., Ltd. TE-031 has a methoxy group at position 6 in its structure. In the present study, we carried out laboratory and clinical investigations on TE-031 in the field of pediatrics. The obtained results are summarized as follows. The antibacterial activity of TE-031 was investigated against 16 clinically isolated strains of Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, Bordetella pertussis and Campylobacter jejuni. TE-031 showed antibacterial activity comparable to erythromycin. The pattern of changes in TE-031 concentrations in the blood after administration was investigated. In subjects administered the granular preparation of TE-031, Cmax values were 0.64 micrograms/ml in 1 subject given a 5 mg/kg dosage, and 5.94 and 9.02 micrograms/ml in 2 subjects administered with 10 mg/kg. The tablet form of TE-031 was administered to 3 subjects at 5 mg/kg, and Cmax values were 2.09-3.92 micrograms/ml, while T 1/2 values were in a range of 2.9-3.8 hours. When drug concentrations in the urine were investigated, it was found that 6-hour recovery rates were 9.9% (dose: 5 mg/kg) and 53.4% (dose: 10 mg/kg) in the subjects administered the granular form, whereas recovery rates averaged 36.8% in the tablet-administered subjects. In the clinical trial, TE-031 was administered in 2-3 doses/day for 2-18 days. In cases given the granular form, dosages were 12-38 mg/kg/day, while tablets were administered at 12-29 mg/kg/day. The overall clinical efficacy rate was 92.8%, i.e., the drug was effective in 64 of 69 patients. TE-031 was ineffective in 1 case of otitis media, but efficacious in 10 of 10 (100%) cases of upper respiratory infection, 15 of 18 (83.3%) cases of bronchitis and pneumonia, 5 of 6 (83.3%) cases of pertussis, 13 of 13 (100%) cases of mycoplasmal pneumonia, 4 of 4 (100%) cases of Chlamydia psittaci pneumonia, 16 of 16 (100%) cases of gastroenteritis (including 15 cases of Campylobacter gastroenteritis), and 1 (100%) case of impetigo. In bacteriological studies conducted on the patients, the overall elimination rate was 93.1%, i.e., bacterial elimination was obtained in 27 of 29 cases. TE-031 showed especially good bacteriological efficacy (100%) against C. jejuni and B. pertussis, which were eliminated from all of 15 and 2 cases examined, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)