5-fluorocytosine and amphotericin B in bronchial secretions

The penetration into and clearance from bronchial secretions of 5-fluorocytosine and amphotericin B were studied in a dog model. After a single intravenous dose of 35 mg/kg, 5-fluorocytosine intrabronchial concentrations were greater than the minimal inhibitory concentration for 80 to 90% of Candida species. These inhibitory concentrations persisted up to 3 h. In contrast, amphotericin B in intravenous doses of 0.6 and 1.2 mg/kg penetrated the blood-bronchus barrier poorly.