In vitro studies with R 51,211 (itraconazole)

The in vitro activity of R 51,211 (itraconazole, accepted generic name; Janssen Pharmaceutica, Beerse, Belgium), a new orally active triazole, was compared with those of two existing orally active azoles, ketoconazole and BAY n 7133, and a topical agent, Ro 14-4767/002. An agar dilution procedure (Kimmig agar) was performed with 148 isolates of pathogenic fungi. Incubation was at 30 degrees C from 48 h to 7 days. R 51,211 was dissolved in 0.2 N HCl in absolute ethanol, ketoconazole was dissolved in 0.2 N HCl alone, BAY n 7133 was dissolved in absolute ethanol, and Ro 14-4767/002 was dissolved in dimethyl sulfoxide. R 51,211 and Ro 14-4767/002 were the most active drugs against isolates of Histoplasma capsulatum, and R 51,211 showed the greatest activity in vitro against isolates of Blastomyces dermatitidis and Cryptococcus neoformans. Ro 14-4767/002 was the most active drug against 30 isolates of dermatophytes, followed by R 51,211, ketoconazole, and BAY n 7133. R 51,211 showed the best activity in vitro against 19 isolates of Aspergillus fumigatus and Aspergillus flavus, as well as 19 isolates of dematiaceous fungi. All four drugs had 90% MICs of greater than or equal to 16 micrograms/ml when tested with isolates of zygomycetous fungi.