Influence of orally administered polyene antimycotics on the intestinal colonization with yeasts: Possibilities and limitations

On the basis of intestinal yeast colonization different consequences for therapeutic and prophylactic administration of polyene antimycotics have to be drawn. Immunocompromised neutropenic patients should orally receive polyene antifungal drugs (nystatin or amphotericin B) for a long time during the period of increased risk for systemic candidosis. The level of daily dosing is dependent on age, physiological status of the gastrointestinal tract, and underlying disease of the patient. In immunocompetent persons the normal commensal yeast flora should not be suppressed by antifungal chemoprophylaxis if no clinical indications are present, because permanent eradication of yeast in the intestinal tract ist not attainable. About 5 to 15 days after finishing the administration of polyene antimycotics the fungi are detectable again in the faeces in low quantities. The influence of orally administered polyene drugs in the intestinal tract may be detected shortly after starting the application. Thus efficient concentrations of nystatin and amphotericin B are continuously present in the faeces 24 to 48 hours after beginning until 2 to 10 days after finishing the administration. During this time the quantity of yeast in the faeces is evidently reduced or not longer detectable by fungal culture. The oral administration of polyene antimycotics for a long time in persons without immunodepression and without heavy intestinal yeast colonization is not justified.