The inhibitory effect of 5-fluorocytosine on fungi is due to the fact that it enters the cells of sensitive fungi and deamines to form the anti-metabolite 5-fluorouracil under the action of cytosine deaminase. The latter is converted into 5-fluorouracil deoxyriboside and inhibits thymidine nucleoside synthase, blocking the conversion of uracil deoxyriboside to thymidine nucleoside and affecting the synthesis of DNA. It has a good inhibitory effect on candida, cryptococcus and geothrix, and also has an effect on some aspergillus, cladospora and bottle fungi that cause dermatomycosis.

Application:

Antifungal drugs. It is mainly used for cutaneous mucosal candidiasis, candidal endocarditis, candidal arthritis, cryptococcal meningitis and pigmented mycosis. Blood tests should be performed regularly during medication. Use with caution in patients with blood diseases of liver and renal insufficiency and pregnant women; Contraindication in patients with severe renal insufficiency.

Adverse reaction:

5-fluorocytosine can have nausea, vomiting, anorexia, diarrhea, rash, fever, anemia, elevated aminotransferase, cell and thrombocytopenia and other adverse reactions. Blood cells and thrombocytopenia are seen, and occasionally liver necrosis, pancytopenia, myelosuppression, and aplastic anemia are seen.