SAN FRANCISCO, CA—The increased use of liposomal amphotericin B (L-AMB) in neonates has occurred without evidence of increased efficacy or safety, presented Siyun Liao, PharmD, from the University of Illinois, Chicago, IL, at IDWeek 2013.

Liposomal formulations of amphotericin were developed to address concerns of nephrotoxicity based mostly on evidence in adult population. Nephrotoxicity associated with deoxycholate amphotericin B (D-AMB) is well documented in adults and has been reported to occur less frequently with L-AMB. However, the incidence of nephrotoxicity associated with amphotericin B use in neonates ranges from 0–60% and is poorly defined among this population.

Read More of MPR’s Exclusive Coverage of IDWeek 2013

Dr. Liao and colleagues performed a retrospective analysis to evaluate nephrotoxicity associated with deoxycholate amphotericin B (D-AMB) and L-AMB use in neonates. The analysis consisted of 75 neonates receiving >1 dose of either D-AMB or L-AMB at a single center between January 1999 and April 2011. Neonates with a baseline SCr >1mg/dL were excluded from this analysis.

Nephrotoxicity was defined as urine output <1mL/kg/hr, or an SCr >0.3mg/dL, or an SCr increase >50% from baseline. From 1999–2006, only 21% of all AMB products prescribed were L-AMB, whereas from 2006–2010, this value was increased to 87%.

Regarding nephrotoxicity, study researchers found no difference as defined by any of the previously described criteria. The incidence of nephrotoxicity ranged from 16–28%, and all neonates had resolution of nephrotoxicity by returning to baseline renal function. The D-AMB treated patients took 4 days to reach resolution whereas the L-AMB treated patients took 3.5 days to  reach resolution. In addition, no significant difference was found in daily fluid intake between D-AMB (142 + 24mL/kg/day) and L-AMB (137 + 11mL/kg/day).

“We did not find a difference in the incidence of nephrotoxicity between D-AMB and L-AMB in our population,” Dr. Liao reported. The team noted that that from previous reports and data, the increased use of L-AMB has occurred without direct efficacy or safety data.

“The use of L-AMB instead of D-AMB to prevent nephrotoxicity in neonates seems unwarranted,” Dr. Liao concluded.