What is the mechanism of action of Ribavirin?

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What is the mechanism of action of Ribavirin?

Ribavirin’s main action is to deplete the pool of guanine nucleotides inside infected cells. It acts as a guanosine analog and inhibits the enzyme inosine monophosphate dehydrogenase, which is needed to convert IMP to GMP. By blocking this step, GTP (and other guanine nucleotides) becomes scarce, limiting viral RNA synthesis because the viral polymerase needs these nucleotides to replicate the genome. This is why the option describing inhibition of guanine nucleotide synthesis is the best choice. Ribavirin does not primarily block viral entry, does not specifically inhibit thymidine nucleotide synthesis, and does not inhibit DNA polymerase; its antiviral effects on RNA viruses stem mainly from limiting guanine nucleotides (and, to some extent, promoting mutagenesis).

Ribavirin’s main action is to deplete the pool of guanine nucleotides inside infected cells. It acts as a guanosine analog and inhibits the enzyme inosine monophosphate dehydrogenase, which is needed to convert IMP to GMP. By blocking this step, GTP (and other guanine nucleotides) becomes scarce, limiting viral RNA synthesis because the viral polymerase needs these nucleotides to replicate the genome. This is why the option describing inhibition of guanine nucleotide synthesis is the best choice. Ribavirin does not primarily block viral entry, does not specifically inhibit thymidine nucleotide synthesis, and does not inhibit DNA polymerase; its antiviral effects on RNA viruses stem mainly from limiting guanine nucleotides (and, to some extent, promoting mutagenesis).

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