Which antiviral medication can be effective if started within 48 hours of flu symptoms?

Zanamivir is an antiviral medication that is effective when initiated within 48 hours of the onset of flu symptoms. It belongs to a class of drugs known as neuraminidase inhibitors, which work by blocking a viral enzyme necessary for the replication of influenza viruses. By doing so, zanamivir can lessen the severity of the flu, reduce the duration of symptoms, and decrease the risk of complications.

Starting treatment within 48 hours is crucial because antiviral medications have the highest efficacy when administered early in the infection. This timeframe allows the medication to significantly impact the viral replication process before the virus has had the opportunity to spread extensively within the body. The other options, while related to antiviral treatments, do not have the same efficacy or specific indications for treating acute influenza as quickly as zanamivir does.