The first line of defense against swine flu is antiviral medication. The two primary antiviral agents approved for treating H1N1 are Oseltamivir (commonly known as Tamiflu) and Zanamivir (Relenza). These medications are most effective when taken within the first two days of symptom onset. They work by inhibiting the neuraminidase enzyme, which is crucial for the virus's replication and spread within the respiratory tract. Early administration can significantly reduce the severity and duration of the illness, making timely diagnosis and prompt treatment essential for affected individuals.