[Single-dose toxicity studies of prulifloxacin (NM441) in mice, rats and dogs and the active metabolite (NM394) in rats].

Single-dose toxicity studies of prulifloxacin, a new antibacterial agent, were conducted in mice, rats and dogs. In addition, a single-dose toxicity study of (+/-)-6-fluoro-1-methyl-4-oxo-7- (1-piperazinyl)-4H-[1,3]thiazeto[3,2-a]quinoline- 3-carboxylic acid (NM394), an active metabolite of prulifloxacin, was performed in rats. Prulifloxacin was administered orally, intraperitoneally (i.p.) or subcutaneously (s.c.) to mice and rats, and orally to dogs. NM394 was administered intravenously (i.v.) to rats. When prulifloxacin was administered orally or s.c., LD50 values were more than 5000 mg/kg in both sexes of mice and rats; when it was administered i.p., LD50 values were 1757 mg/kg in male mice, 1652 mg/kg in female mice, 915 mg/kg in male rats, and 1076 mg/kg in female rats. The lethal doses of this drug were more than 5000 mg/kg in both sexes of dogs by the oral route. The LD50 values of NM394 were 226 mg/kg in male rats and 238 mg/kg in female rats by the i.v. route. In mice, the major clinical signs observed following the administration of prulifloxacin were sedation, oligopnea, abnormal gait, piloerection, closed eye and tremor by the i.p. route and a scab at the site of injection by the s.c. route; in rats, decreased spontaneous locomotor activity by any of the three routes, oligopnea, lacrimation, hypothermia, piloerection and abnormal gait by the i.p. route, and a scab at the site of injection by the s.c. route; and in dogs, vomiting, reddening of the skin, and loose stool by the oral route. When NM394 was administered i.v., rats showed clonic convulsion and dyspnea. The site of injection was hyperemic, swollen and necrotic. Mice showed a decrease in body weight or an inhibition in weight gain when prulifloxacin was administered i.p. and rats showed the same effects when prulifloxacin or NM394 was administered by any of the above-mentioned routes. Macroscopic findings detected following the i.p. administration of prulifloxacin in mice were pale color of the liver and spleen, thickening of the liver, and adhesion of intra-abdominal organs; and in rats, hydrothorax, congestion and edema of the lung, adhesion of intra-abdominal organs, swelling of the kidney accompanied by fine yellowish-white foci, and atrophy of the testis. When NM394 was administered i.v. to rats, congestion of the lung was macroscopically observed.