Correlates of acute renal failure in patients receiving parenteral amphotericin B.

BACKGROUND: While parenteral amphotericin B is an effective therapy for serious fungal infections, it frequently causes acute renal failure (ARF). This study identified correlates of ARF in amphotericin B therapy and used them to develop clinical prediction rules.

METHODS: All 643 inpatients receiving parenteral amphotericin B therapy at one tertiary care hospital were included. Data regarding correlates were obtained both electronically and from manual chart review in a subsample of 231 patients. ARF was defined as a 50% increase in the baseline creatinine with a peak > or =2.0 mg/dL.

RESULTS: Among 643 episodes, ARF developed in 175 (27%). In the larger group, the only independent correlate of ARF was male gender (OR = 2.2, 95% CI, 1.5 to 3.3). In the subsample (N = 231), independent correlates of ARF were maximum daily amphotericin dosage, location at the time of initiation of amphotericin therapy, and concomitant use of cyclosporine. These data were used to develop two clinical prediction rules. A rule using only data available at initiation of therapy stratified patients into groups with probability of ARF ranging from 15 to 54%, while a rule including data available during therapy (maximum daily dose) stratified patients into groups with probability of ARF ranging from 4 to 80%.

CONCLUSIONS: Acute renal failure occurred in a quarter of the patients. Correlates of ARF at the beginning and during the course of amphotericin therapy were identified and then combined to allow stratification according to ARF risk. These data also provide evidence for guidelines for the selection of patients for alternative therapies.