非西他滨, Fiacitabine

Fiacitabine, also known as FIAC or DRG-0077, is a pyrimidine nucleoside analog reported to elicit potent anti-VZV activity both in vitro and in vivo. Fiacitabine has potent antiviral activity in vivo against herpes simplex virus types 1 and 2 and cytomegalovirus. Fiacitabine is therapeutically superior to ara-A for the treatment of varicella-zoster virus infections in immunosuppressed subjects.

Fiacitabine is an antimicrobial agent that inhibits microbial growth by binding to the ribosomal 30S subunit and blocking protein synthesis. It is a prodrug that is converted to 5-fluorocytosine (5FC) in the liver, where it inhibits the activity of the enzyme dihydropyrimidine dehydrogenase, thereby interfering with DNA replication. Fiacitabine has been shown to be effective against infections caused by bacteria and fungi. In vitro studies have shown that fiacitabine binds to toll-like receptor 4 (TLR4), which may lead to its cytostatic effects. Fiacitabine also inhibits proliferation of HL60 cells in a dose-dependent manner.