Systemic absorption of amphotericin B with topical 5% mafenide acetate/amphotericin B solution for grafted burn wounds: is it clinically relevant?

Abstract

To determine if patients receiving topical amphotericin B in combination with 5% mafenide acetate solution will acquire systemically detectable levels of amphotericin B. A prospective, observational study of consecutive patients from May 2007 to March 2008 who received 5% mafenide acetate/amphotericin B (2 mcg/ml) solution topically every 4h to their excised and grafted burn wounds for at least 5 days. Serum amphotericin B levels were measured every 5 days during treatment. In addition, the percentage of graft take, occurrence of infection, and potential adverse reactions or toxicities were monitored and recorded. A total of 27 patients were enrolled, accumulating 420 treatment days and 72 amphotericin B levels. Sixty-nine of the amphotericin B levels were undetectable, while 3 were detectable at non-therapeutic levels (<0.5 mcg/ml). Of the patients with a detectable serum amphotericin B level, only one experienced adverse reactions that could potentially be attributed to amphotericin B. The mean TBSA burned was 32% (SD+/-14%), with a mean TBSA treated with solution of 21% (SD+/-13%). The median duration of treatment was 8 days (range 5-52 days), and the median number of amphotericin B levels drawn per patient was 1 (range 1-19). The median percentage graft take was 95%, and there were no fungal wound infections. We conclude that 5% mafenide acetate/amphotericin B (2 mcg/ml) solution, applied to excised and grafted burn wounds, does not produce clinically relevant serum levels of amphotericin B. Based on our observations, this topical regimen is safe.