Therapeutic effect of the triazole Bay R 3783 in mouse models of coccidioidomycosis, blastomycosis, and histoplasmosis.
A new triazole, Bay R 3783, was compared with ketoconazole, itraconazole, and fluconazole, which were given via the alimentary tract at three dosages, and amphotericin B, which was given at 1 mg/kg intraperitoneally, in murine models of the systemic mycoses coccidioidomycosis, histoplasmosis, and blastomycosis. In a pulmonary coccidioidomycosis model, Bay R 3783, fluconazole, and itraconazole were essentially equally efficacious and more active than ketoconazole in protecting mice against death; but they were inferior to amphotericin B. In a short-term organ load experiment, Bay R 3783 and amphotericin B were equally effective and were more effective than the other drugs in reducing the amount of Coccidioides immitis in the lungs. Against meningocerebral coccidioidomycosis, Bay R 3783, itraconazole, and fluconazole at 25 mg/kg and amphotericin B prevented death only during therapy, with mortalities ensuing shortly thereafter. In mice with systemic histoplasmosis, Bay R 3783 and itraconazole at 25 mg/kg and amphotericin B prevented death in all mice through a 44-day observation period. Clearance of Histoplasma capsulatum from organs was similar in mice treated with Bay R 3783 and itraconazole; this clearance was greater than that in mice treated with ketoconazole and fluconazole but less than that in mice treated with amphotericin B. In mice with systemic blastomycosis, Bay R 3783 at 25 mg/kg yielded 90% survivors at 60 days, which was greater than that achieved with amphotericin B (60%) or itraconazole (30%). Clearance of Blastomyces dermatitidis from the lungs was greatest with Bay R 3783, followed by that with amphotericin B, itraconazole, fluconazole, and ketoconazole, in that order. Therefore, Bay R 3783 showed effectiveness comparable to or exceeding those of itraconazole and fluconazole and exceeding that of ketoconazole against these systemic mycoses in mice.
Pappagianis
D
D
Department of Medical Microbiology, School of Medicine, University of California, Davis 95616.
Zimmer
B L
BL
Theodoropoulos
G
G
Plempel
M
M
Hector
R F
RF
D000818:Animals; D000935:Antifungal Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D001681:Biological Assay; D001759:Blastomycosis / Q000188:drug therapy*; D003047:Coccidioidomycosis / Q000188:drug therapy*; D004195:Disease Models, Animal; D005260:Female; D006660:Histoplasmosis / Q000188:drug therapy*; D051379:Mice; D008826:Microbial Sensitivity Tests; D015996:Survival Rate; D014230:Triazoles / Q000493:pharmacokinetics / Q000627:therapeutic use*
D000935:Antifungal Agents; D014230:Triazoles; C063929:Bay R 3783