Ribavirin triphosphate (RTF) is a potent inhibitor of inosine monophosphate dehydrogenase (IMP dehydrogenase), viral RNA polymerase and viral mRNA-guanylyltransferase. Inhibition of the latter stops capping mRNA, which leads to a significant depletion of intracellular reserves of guanosine triphosphate and inhibition of the synthesis of viral RNA and protein.
Ribavirin is also built into the viral genome, causing lethal mutations, with a subsequent decrease in the pathogenicity of the virus.
Ribavirin inhibits the replication of new virions, which reduces the viral load, selectively inhibits the synthesis of viral RNA, without suppressing the synthesis of RNA in normally functioning cells. The most sensitive to ribavirin DNA viruses are herpes simplex virus, adenoviruses, CMV, smallpox viruses, Marek's diseases; RNA viruses - influenza A, B viruses, paramyxoviruses (parainfluenza, mumps, Newcastle disease), reoviruses, arenaviruses (Lassa fever virus, Bolivian hemorrhagic fever), bunyaviruses (Rift Valley fever virus, Crimean-Congo hemorrhagic fever virus), hantaviruses (haemorrhagic fever virus with renal or pulmonary syndrome), oncogenic RNA viruses.
Ribavirin-insensitive DNA viruses: Varicella zoster, pseudorabies virus, cowpox; RNA viruses: enteroviruses, rhinoviruses, encephalitis virus of the forest Semliki.