Fosfomycin in the treatment of bacterial infections: summary of clinical trials in Japan.

The Japan Research Committee of Fosfomycin was organized in the fall of 1972 to promote the basic and clinical studies on fosfomycin. First of all, a subcommittee of fosfomycin consisting of a limited number of members was organized to establish the methods of determination on its antibacterial activity and its concentration in the biological fluid, and the most applicable methods were devised. The clinical trials on its oral form in a small scale were commenced from spring in 1973, and then gradually expanded to almost all of Japan. The clinical trials on its parenteral intravenous form were also undertaken from the latter half of 1973. The basic and clinical results obtained from hospitals and institutes almost all over Japan, to which members of the above Committee belong, were presented by speakers under a hot discussion in two symposia which were held by the Japan Society of Chemotherapy; one on its oral form in June 1974, and another on its parenteral form in December 1974. I served as chairman in both of the symposia. The clinical results of fosfomycin in Japan which were mainly collected in both symposia are described below. Its antibacterial activity, and absorption and exretion will be presented elsewhere in this volume. Clinical results of its oral form: Dosage forms of fosfomycin-Ca salt, capsule and granules, were prepared for its clinical trials. It resulted effective in about 76% of 1,200 patients with infection due to gram-positive or gram-negative (Pseudomonas, Salmonella, Escherichia coli, etc.) bacteria in several fields. As far as rates of efficacy were concerned, it was more effective in surgical, urological, ophthalmic and some other fields than in internal and pediatric ones. Fosfomycin was given in a dose of 2-3 g/day for adults or 100-130 mg/kg for infants and children in most cases. Furthermore, it can be favorably mentioned that fosfomycin was proved to be effective in salmonellosis and resistant shigellosis by a certain research group specialized in the therapy of infectious enteritis. Clinical results of its parenteral form: Sterlized bulk material of fosfomycin-Na salt was prepared in a vial for clinical use. Similarly as in the case of oral form, it was applied to about 500 patients with several infections. It resulted effective in about 68% of them. This percentage was not as high because of the higher frequency of application to severe patients or patients with underlying disease. Fosfomycin was intravenously administered by one shot or drip infusion in a dose of 2-4 g/day for adults, or 100-250 mg/kg for infants and children in most cases. Adverse reactions: In oral form, the incidence of adverse reactions was about 10% but most of them were slight gastrointestinal disorders. In an extremely small number of patients a rise of SGOT and/or SGPT was observed. In parenteral form, the incidence of adverse reactions was a little higher, being about 17% including a rise of SGOT and/or SGPT, vascular pain, nausea, and vomiting, etc...