Histamine-releasing properties of T-3762, a novel fluoroquinolone antimicrobial agent in intravenous use. II. Dermovascular permeability-increasing effect and action on peritoneal mast cells.

To predict the actions of T-3762, a newly developed fluoroquinolone antimicrobial agent, as well as ciprofloxacin (CPFX) and ofloxacin (OFLX), on injection sites when dosed parenterally, their ability to increase cutaneous vascular permeability in dogs and to release histamine from rat peritoneal mast cells was examined. CPFX and OFLX increased cutaneous vascular permeability in concentrations ranging from 16 to 32 microg/ml, while T-3762 was inactive at 2000 microg/ml. The vascular permeability-increasing activities of these drugs were inhibited efficiently by pretreatment with a combined dose of diphenhydramine and cimetidine. CPFX induced histamine release from rat mast cells in a dose-dependent manner, whereas T-3762 was ineffective. Therefore, it is concluded that fluoroquinolone antimicrobial agents may have the ability to cause an increase in cutaneous vascular permeability by releasing histamine from mast cells at the injection site when administered parenterally, and that T-3762 has minimum activity among the agents tested in this study.