[Pharmacokinetic, bacteriological, and clinical studies on SY5555 in children]

Pharmacokinetic, bacteriological and clinical studies on SY5555 were performed in children. The results were as follows: 1. A total of 15 patients considered to have bacterial infections were treated with SY5555. Each dose, 5 mg/kg, was orally administered 3 times daily, for 4-11 days. Clinical efficacies of SY5555 in 13 patients with bacterial infections (1 with pneumonia, 2 with bronchitis, each 1 with maxillary sinusitis, 2 with otitis media, 5 with pharyngitis, 1 each with gastroenteritis and pyelonephritis) were evaluated as excellent in 10 patients and as good in 3 patients with an efficacy rate of 100%. Two patients with viral infection and malignant lymphoma were not evaluated. Thirteen causative strains in 7 species were found in 10 patients. Streptococcus pneumoniae in 1/3, Haemophilus influenzae in 2/2, Streptococcus pyogenes 4/4, Salmonella spp. in 1/1, Escherichia coli in 1/1 were eradicated. Only one patient developed mild diarrhea as an adverse reaction. Another patient showed elevated GPT (glutamate pyruvate transaminase). The abnormality was mild and the patient recovered after the cessation of SY5555 administration without specific treatment. 2. MICs of SY5555 were examined against 33 clinical isolates. SY5555 has low MICs against Enterococcus faecalis and other Gram-positive cocci. 3. Pharmacokinetic studies Peak plasma concentrations of SY5555 was 1.15 micrograms/ml at a dose level of 4.9 mg/kg orally administered at fasting. Based on the above results and the broad spectrum of the anti-bacterial activities, SY5555 appears to be a promising antibiotics that is usable as a single agent for the primary therapy of respiratory tract infections, skin soft tissue infections and urinary tract infections in children.