Amphotericin B is often associated with numerous side effects including nephrotoxicity and an infusion-related phenomenon marked by hypotension, fever, chills, and rigors. In an effort to alleviate these side effects, three different lipid-based products have been developed: liposomal amphotericin B (L-AMB), amphotericin B lipid complex (ABLC), and amphotericin B colloidal dispersion (ABCD). It is important to note that these products should not be considered interchangeable, as each has different pharmacokinetic and physiochemical characteristics (see Table 251.1).

Amphotericin B–related nephrotoxicity occurs presumably as a result of its vasoconstrictive effects, as well as direct effects on the epithelial cell membranes and tubular dysfunction. Other renal toxicities associated with amphotericin B include potassium- and magnesium-wasting syndromes as well as renal tubular acidosis. As a result, a reversible decline in glomerular filtration rate (GFR) and a rise in serum creatinine up to as high as 2.5 mg/dL is not uncommon during a course of therapy. However, the resultant reduction in renal blood flow and GFR can also precipitate necrosis and acute renal failure (ARF) in some patients. Patients at greatest risk for developing ARF

are the critically ill and patients receiving concomitant nephrotoxins (e.g., cyclosporine, aminoglycosides). Numerous studies consistently suggest that lipid-based amphotericin products are associated with at least 50% less renal toxicity as compared with conventional amphotericin B. However, it is still important to note that nephrotoxicity and renal failure can still develop with the lipid-based products; therefore, close monitoring of urine output, electrolytes, blood urea nitrogen, and serum creatinine is warranted in all patients.