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

ObjectiveTo determine if patients receiving topical amphotericin B in combination with 5% mafenide acetate solution will acquire systemically detectable levels of amphotericin B.MethodsA 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 4 h 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.ResultsA 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.ConclusionsWe 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.