Ribavirin is a multifunctional inhibitor of RNA virus replication

 The purine (Adenine and Guanine) analogue ribavirin is a synthetic antiviral ribonucleoside (ribose + base) with activity against a broad spectrum of RNA viruses. Ribavirin monophosphate (RMP) is an inhibitor of inosine monophosphate dehydrogenase that is required for the synthesis of guanine nucleotide, causing a reduction of guanine nucleotide pool in cells, which results in the inhibition of newly viral RNA synthesis. Moreover, ribavirin triphosphate (RTP) acts as an substrate of viral RNA dependent RNA polymerases, leading to the lethal mutagenesis of viral genome RNA via the incorporation of the RTP as an inappropriate substrate NTP.