Laboratory and clinical evaluation of S-1108 for respiratory tract infections

A newly developed broad-spectrum cephem, S-1108, was evaluated in vitro and in vivo. The results were as follows. 1. Antimicrobial activity : Minimal inhibitory concentrations (MICs) against 3 standard strains and 298 clinical isolates, including 10 different species, were determined and compared with three other antibiotics, CFTM, CTM and CCL. S-1006, an active form of S-1108, showed excellent antimicrobial activity against both gram-positive and gram-negative bacteria, except E. cloacae and P. aeruginosa, and the MICs were the same or greater than those of the other three drugs. 2. S-1006 concentration in serum and sputum : Two patients with chronic bronchitis were given 200 mg of S-1108 orally, and its concentrations in serum and sputum were measured at intervals using HPLC or bioassay. The peak concentrations of S-1006 in serum were 2. 42μg/ml and 2.94μg/ml, while, the peak concentration in sputum was 0.07 μg/ml in the former patient, and the penetration ratio was 2.9%. 3. Clinical efficacy and adverse reactions : Eighteen patients with respiratory tract infections were treated with S-1108, and the overall efficacy ratio was 83.3% (excellent in 3 cases, good in 12, fair in 2 and poor in 1). Adverse reactions were cutaneous pruritus in one patient, anorexia in 1, nausea in 1 and diarrhea in 1. Elevation of CPK was observed in 1 case as an abnormal laboratory finding. All of the above were mild and improved repidly after completion of S-1108 treatment, indicating that S-1108 is a very safe agent.