Which amphotericin B formulation is associated with the lowest risk of nephrotoxicity?

• A. Conventional amphotericin B
• B. Oral amphotericin B
• C. Lipid formulations
• D. Topical amphotericin B

Answer: (C)

Lipid formulations reduce kidney toxicity by changing how amphotericin B is distributed in the body. The conventional formulation can concentrate in the kidneys and cause direct tubular injury plus reduced renal blood flow, leading to nephrotoxicity. Encapsulating amphotericin B in lipid carriers (liposomal, lipid complex, or colloidal dispersion) lowers renal exposure to the drug, decreases free drug in circulation, and still delivers effective antifungal activity to infected sites. Oral amphotericin B isn’t practical systemically due to poor bioavailability, and topical formulations aren’t used for systemic infections, so among systemic options, lipid formulations have the lowest nephrotoxicity risk.