Nystatin pastilles and suspension in the treatment of oral candidosis.

Clinical audit revealed that the treatment of oral candidosis was more successful with nystatin pastilles than with nystatin suspension. The purpose of this investigation was to determine the reasons for this observation. The concentration of nystatin needed to kill 49 consecutive clinical isolates of Candida albicans was measured. The isolates varied in cidal concentrations from 1.875 to 30 U/ml. The time taken to kill these isolates at their cidal concentrations was found to vary from 120 to 300 min. Volunteer studies showed that antifungal activity in the oral cavity was eliminated rapidly after the use of nystatin suspension. In contrast, the polyene could be detected for at least 5 hours after use of the nystatin pastille. The nystatin pastille can be expected to be more effective at killing Candida albicans than the suspension due to its persistent effects.