The role of second-generation triazole antifungal agents voriconazole and posaconazole in patients with hematologic malignancies

The second-generation triazoles, voriconazole and posaconazole, have found important roles in the management of invasive fungal infections in high-risk patients. Both agents are more active against Candida albicans and the non-albicans Candida species than the first-generation triazoles. They are active against Aspergillus species, including those species less susceptible to polyenes, and against a variety of non-Aspergillus molds. In contrast to posaconazole, voriconazole has no activity against the zygomycetes, and breakthrough infections have been observed. Both are well absorbed, but considerable intra- and interpatient pharmacokinetic variability has raised the question of therapeutic drug monitoring. Both inhibit hepatic cytochrome P450 isoenzymes, which are important in the metabolism of various drugs coadministered in the management of high-risk patients. Clinical trials have demonstrated the safety and efficacy of both agents for antifungal prophylaxis and treatment in invasive candidiasis, invasive aspergillosis, and in invasive fungal infections caused by a variety of non-Aspergillus molds. Posaconazole is the only triazole approved for use in the treatment of invasive zygomycosis. Voriconazole is the accepted standard first-line therapy for invasive aspergillosis.