Final answer:
Ribavirin appears to interfere with DNA and RNA synthesis and inhibits RNA polymerase of hepatitis C, but its MOA is not fully understood. It's used against RNA viruses, but can have serious side effects.
Step-by-step explanation:
The mechanism of action (MOA) of Ribavirin, a synthetic guanosine analog, is complex and not entirely understood; it is believed to interfere with both DNA and RNA synthesis, likely by reducing the intracellular guanosine triphosphate (GTP) pools. Ribavirin also seems to inhibit the RNA polymerase of the hepatitis C virus, and is used primarily against RNA viruses, including hepatitis C (in combo therapy with interferon) and respiratory syncytial virus. Despite the therapeutic benefits, side effects like anemia and potential harm to unborn children during pregnancy are significant considerations. Unfortunately, the MOA of 'Microphenylate' is not provided in the reference information available, which suggests it may not be a recognized antiviral medication, or could be a typo that needs clarification.