Studies on the antimycotic activity of 5-fluoroorotic acid

The antimycotic effect of 5-fluoroorotic acid (FOA) was studied in experimental and clinical conditions. The experiments in vitro were performed on 21 strains of fungi isolated mainly from clinical material. The effect of FOA was compared with those of the structurally related drug 5-fluorocytosine. The clinical study was performed on 40 patients aged 18 to 75 years with mycological diseases. FOA in different dosage forms was applied topically 2 to 3 times daily for 30 days. Microscopic and cultured mycological studies were performed before and after treatment. The results showed that FOA possesses a well-expressed anticandidal effect close to that of 5-fluorocytosine, as well as moderate antidermatophytal effects. Clinical studies of 1% FOA cream showed good therapeutic effects similar to that of Ung. Whitfield, but 55% of the patients developed relapse of the lesions after discontinuation of the treatment. Higher concentrations of FOA included in milk suspension and powder induced severe side effects of local irritability.