A prospective and retrospective analysis of the nephrotoxicity and efficacy of lipid-based amphotericin B formulations.

STUDY OBJECTIVE: To determine the usage patterns of the lipid-based amphotericin B formulations at our institution and to compare the observed nephrotoxicity and efficacy of these formulations.

DESIGN: Prospective and retrospective observational study

SETTING: Urban 350-bed teaching hospital.

PATIENTS: Sixty-seven nonhemodialysis patients who were prescribed greater than 3 days of amphotericin B lipid complex (ABLC) or liposomal amphotericin B (L-AmB) from 1996-1999.

MEASUREMENTS AND RESULTS: Forty-six patients received ABLC and 21 received L-AmB. Oncology patients accounted for most prescriptions of both formulations. Amphotericin B lipid complex most frequently was prescribed for treatment of documented fungal infections (50%), followed by treatment of neutropenic fever (33%). Liposomal amphotericin B most frequently was prescribed for treatment of neutropenic fever (62%), followed by treatment of documented fungal infections (29%). Seventy-eight percent of patients treated with ABLC and 90% of those who received L-AmB were started on the lipid-based formulation due to being refractory or intolerant to prior antifungal therapy. Two (4.4%) patients receiving ABLC and four (19%) patients receiving L-AmB experienced nephrotoxicity at the end of therapy (NS). Of the patients with a documented fungal infection, 20 out of 23 (87%) of those treated with ABLC and 4 out of 5 (80%) of those treated with L-AmB had a complete or partial response to therapy (NS). One patient with febrile neutropenia had a breakthrough fungal infection while receiving L-AmB.

CONCLUSION: No significant differences in nephrotoxicity or efficacy were found between ABLC and L-AmB. Until further studies indicate clinically significant differences in nephrotoxicity between the two liposomal amphotericin B formulations, it is recommended that economics continue to be the major determinant for product selection.