The lipid formulations of amphotericin B

Amphotericin B spectrum covers most of the fungal pathogens involved in human diseases. Its use is limited by infusion-related effects and nephrotoxicity. As a result of strong lipophilic properties, encapsulation in liposomes or binding to lipid complexes led to the development of lipid formulations in an attempt to increase both efficacy and safety. Three lipid formulations of amphotericin B are commercially available: a liposomal preparation, a lipid complex and a colloidal dispersion. They differ in their lipid composition, shape, pharmacokinetic behaviour and clinical effects. The nephrotoxicity of these formulations is significantly decreased compared to their parent compound. Infusion-related events are lowest with liposomal amphotericin B. Increased efficacy of the lipid formulations over conventional amphotericin B, however, still has to be demonstrated. These formulations are mainly indicated for the treatment of documented fungal infections in patients failing conventional amphotericin B or with renal impairment. Liposomal amphotericin B is also indicated for empirical therapy of suspected fungal infections in febrile neutropenic patients giving this compound an advantage over the two other formulations. Lipid formulations of amphotericin B are extremely expensive. Whether the increase in cost translates into a long-term benefit for the patient is still unknown.