Combined action of amphotericin B and 5-fluorocytosine on pathogenic yeasts susceptible to either drug alone.
Amphotericin B (AMB)-5-fluorocytosine (5-FC) synergism has generally been observed in yeasts displaying 5-FC resistance. The present study was designed to assess activity of these drugs on yeasts showing susceptibility to 5-FC as well as AMB. Selected strains were incubated in a synthetic liquid medium with the test agents and viability or 14C-5-FC uptake was determined. Combinations of AMB and 5-FC continued to be inhibitory during the period that cultures treated with either drug alone were recovering from transient inhibition. In this sense, AMB + 5-FC exerted greater antifungal activity than either drug alone. However, combined activity did not involve AMB stimulation of 5-FC uptake by the organism. Results were indicative of sequential drug action.
D000666:Amphotericin B / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects; D003596:Cytosine / Q000031:analogs & derivatives*; D004357:Drug Synergism; D005437:Flucytosine / Q000378:metabolism / Q000494:pharmacology*; D015003:Yeasts / Q000187:drug effects*
D000666:Amphotericin B; D003596:Cytosine; D005437:Flucytosine