The value of amphotericin B in the treatment of invasive fungal infections

Over the last 20 years, there has been an increase in the total number of invasive fungal infections (IFIs) and in infections caused by rare and emerging pathogens. This is due in part to the growing population of immunocompromised patients at risk of developing fungal infections. Three classes of antifungal agents are widely used for the treatment of systemic fungal infections: polyenes, azoles, and echinocandins. Polyenes were the first antifungal agents developed and have a long-standing history in the treatment of IFIs. The use of conventional amphotericin B has been limited because of toxic side effects, which have been reduced by the lipid formulations of amphotericin B. Treatment options for invasive mycoses have expanded with the recent introduction of the second-generation triazoles (voriconazole and posaconazole) and the echinocandins (caspofungin, micafungin, anidulafungin). Despite the increased number of antifungal drugs, resistance issues present a problem in the treatment of IFIs. Although some fungal pathogens display innate resistance, others have developed resistance secondary to selective pressure. This article briefly reviews the changing epidemiology of fungal infections and associated risk factors, resistance issues with commonly administered antifungal agents, and treatment options for IFIs, with a focus on polyenes.