Ribavirin

Ribavirin is a synthetic guanosine nucleoside analogue used against certain viral infections. Its antiviral effects arise through several mechanisms that disrupt viral replication and RNA production.

Nucleoside analogue: A molecule resembling a nucleoside that can interfere with nucleic-acid synthesis or related processes. Ribavirin’s resemblance to guanosine underlies its antiviral activity.
Hepatitis C: A liver infection caused by hepatitis C virus, which can become chronic and lead to cirrhosis or liver cancer. Ribavirin was a component of earlier combination regimens and remains relevant in selected treatment settings.
Joseph T. Witkowski: An American medicinal chemist associated with the discovery and development of ribavirin. Witkowski and colleagues synthesized ribavirin during efforts to develop antiviral compounds.
Direct-acting antiviral: An antiviral drug that targets a specific viral protein or replication step. Unlike many direct-acting drugs, ribavirin has multiple proposed effects and limited virus-specific selectivity.
Inosine monophosphate dehydrogenase: An enzyme that catalyzes a rate-limiting step in guanine nucleotide synthesis. Ribavirin monophosphate inhibits this enzyme, reducing the guanosine nucleotide pool available to viruses.
Respiratory syncytial virus: A virus that infects the respiratory tract and can cause severe lower respiratory disease, especially in infants and older adults. Inhaled ribavirin has been used in limited cases of severe RSV infection, particularly in immunocompromised patients.
Nucleoside synthesis: The chemical construction of molecules composed of a nitrogenous base joined to a sugar. Ribavirin’s development relied on synthesizing a modified nucleoside with broad antiviral activity.
Interferon alfa: A signaling protein used therapeutically to stimulate antiviral and immune responses. Ribavirin was often combined with interferon alfa in historical hepatitis C regimens.
Lethal mutagenesis: A process in which mutation rates rise until a replicating population loses viability. Ribavirin triphosphate can promote errors during viral RNA synthesis, potentially pushing some viruses toward extinction.
Lassa fever: A viral hemorrhagic illness caused by Lassa virus, endemic in parts of West Africa. Ribavirin has been used to treat Lassa fever, though the evidence and optimal use remain debated.

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