Antifungal activity of amphotericin

Wasan KM, Rosenblum MG, Cheung L, and Lopez-Berestein G. Influence of lipoproteins on renal cytotoxicity and antifungal activity of amphotericin B. Antimicrob Agents Chemother 38 223-227,1994. 

Table 3. Antifungal activity of amphotericin B in combination with anethole (15).

Orunsi, N. A., Trinci, A. P. J. Growth of bacteria on chitin, fungal cell walls and fungal biomass, and the effect of extracellular enzymes produced by these cultures on the antifungal activity of amphotericin B. Microbiol 1985,43,17-30. 

Yu et al. (1998) were able to increase tha/itno antifungal efLciency of amphotericin B while at the same time decreasing its hemolytic activity by loading the drug into polymeric micelles. It was suggested that polymeric micelles could stabilize amphotericin B against autooxidation and/or enhance membrane perturbation of fungal cells. 

K. M. Wasan and J. S. Conklin, Evaluation of renal toxicity and antifungal activity of free and liposomal amphotericin B following a single intravenous dose to diabetic rats with systemic candidiasis, Antimicrob. Agents Chemother. 40 1806-1810, (1996). 

Finally, there remain some effects of ansamycins of which the significance and the biochemical targets are as yet unknown these include the combined action of rifamycin and amphotericin B on fungal cells, and the antibacterial and antifungal activity of naphthomycin and geldanamycin. 

Walsh TJ, Peter J, McGough DA, Fothergill AW, Rinaldi MG, Pizzo PA. Activities of amphotericin B and antifungal azoles alone and in combination against Pseudallescheria boydii. Antimicrob Agents Chemother 1995 39(6) 1361. ... 

Anaissie E, Paetznick V, Proffitt R, et ai. Comparison ofthe in vitro antifungal activity of free and liposome-encapsulated amphotericin B. Eur J Clin Microbiol Infect Dis 1991 10 665-8. 

New RRC, Chance ML, Heath S. Antileishmanial activity of amphotericin and other antifungal agents entrapped in liposomes. J Antimicrob Chemother 1981 8 371-381. 

Furthermore, the antifungal actions of amphotericin B are enhanced by flucytosine, minocycline, or rifampin, agents otherwise devoid of antifungal activity. 

A l t - to 20-day test system was reported for evaluating the in vivo antifungal activity of compounds against experimental infections of ocardia asteroides, Histoplasma capsulatum, and Paracoccidioide s brasITTensis.Efficacy was based on extension of the mean survival time of untreated as compared with treated mice the 50 effective dose (ED50) was determined for sulfonamides, amphotericin B, and saramycetin. 

Amphotericin B is particularly effective against systemic infections caused by C. albicans and Cryptococcus neoformans. It is poorly absorbed from the gastrointestinal tract and is thus usually administered by intravenous injection under strict medical supervision. Amphotericin B methyl ester (Fig. 5.15C) is water-soluble, unlike amphotericin B itself, and can be administered intravenously as a solution. The two forms have equal antifungal activity but higher peak serum levels are obtained with the ester. Although the ester is claimed to be less toxic, neurological effects have been observed. An ascorbate salt has recently been described which is water-soluble, of similar activity and less toxic. 

Topical formulations of nystatin and of amphotericin B are useful in the management of Candida albicans infections of the skin. Both antibiotics are ineffective against dermatophytes. The use of nystatin is limited to topical treatment of cutaneous and mucosal Candida infections because of its narrow spectrum and its negligible absorption from the gastrointestinal tract. Hypersensitivity reactions are rare. It is not known whether topical nystatin can cause fetal harm when used by a pregnant woman. Amphotericin B has broader antifungal activity but its topical use is restricted to Candida. Topical use of amphotericin B has shown minimal absorption through the skin and is well tolerated. Limited human surveillance data do not indicate any harm to mother or fetus, but relative safety is still unknown. 

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