Prophylaxis of Invasive Fungal Infections: A Review of the Use of Posaconazole

Invasive fungal infections (IFIs) cause significant morbidity, mortality, and increased cost of care in patients with hematological malignancies, prolonged (i.e. >7–10 days) treatment induced neutropenia, and other disease states causing underlying immunosuppression. One strategy often used to combat the development of invasive infections is the use of antifungal agents as prophylaxis in at risk patients. Posaconazole is an oral triazole with a useful spectrum of activity against many fungal pathogens of concern in patients at risk for the development of IFIs. Posaconazole is only available in oral formulation and therapeutic drug monitoring may provide value due to variable absorption and serum concentrations. Clinical efficacy and pharmacoeconomic data have demonstrated the utility of posaconazole in the treatment of oropharyngeal candidiasis and for prophylaxis in patients at risk for development of IFIs. Several organizations or expert groups involved in developing guidelines for the management of IFIs recommend posaconazole anti-fungal prophylaxis in patients with AML or MDS and chemotherapy induced neutropenia or significant GVHD. In addition, nonrandomized studies (largely of salvage therapy) and case series suggest that posaconazole may be effective as treatment for invasive aspergillosis, zygomycosis, and coccidiomycosis. Further, small case series or individual case reports suggest activity against other less commonly encountered filamentous fungi and Histoplasma.