ABSTRACT
SCH 39304 (304) and its isomers, SCH 42426 (426) and SCH 42427 (427), are new orally administered antifungal azole derivatives. In this study, we compared the efficacy of 304 with that of 426 and 427 in murine models of cryptococcal and coccidioidal meningitis. On day 18 postinfection with Cryptococcus neoformans, controls showed 80% mortality. The 50% protective doses calculated at this day were 0.56 mg of 304 per kg of body weight, 23.5 mg of 426 per kg, and 0.11 mg of 427 per kg. Controls with coccidioidal meningitis all succumbed, and treated mice at the same time point showed 50% protective doses of 10.8 mg/kg for 304, 200 mg/kg for 426, and 2.1 mg/kg for 427. We conclude that isomer 427 is five times as potent, whereas 426 is 1/50th as potent as 304 in these experimental mycoses.
Subject(s)
Antifungal Agents/therapeutic use , Coccidioidomycosis/drug therapy , Meningitis, Cryptococcal/drug therapy , Triazoles/therapeutic use , Administration, Oral , Animals , Azoles/blood , Coccidioides/drug effects , Coccidioidomycosis/mortality , Cryptococcus neoformans/drug effects , Culture Techniques , Isomerism , Meningitis, Cryptococcal/mortality , MiceABSTRACT
To assess the possible beneficial effects of combined therapy (fluconazole and flucytosine) in the treatment of cryptococcal meningitis in the immunocompromised host, we compared therapy with fluconazole and flucytosine, individually and combined, in the experimental murine model. BALB/c athymic (nu/nu) mice were infected intracerebrally with 150 to 300 CFU of Cryptococcus neoformans. In mortality studies, treatment was initiated 24 h postinfection and continued for 10 to 14 days with either fluconazole (1 to 15 mg/kg of body weight per day), flucytosine (60 to 120 mg/kg/8 h), both drugs, or 0.3% Noble agar (control). Combined therapy delayed mortality significantly when compared with controls and single-drug regimens. This was observed over a broad range of doses. Quantitative determinations of CFU in brain tissue demonstrated a significantly lower burden of C. neoformans in mice receiving combined therapy. The results indicate that combined therapy with fluconazole and flucytosine is superior to single-drug therapy.
