Oseltamivir and zanamivir are effective for prophylaxis and post-exposure prophylaxis, and research overall indicates that NA inhibitors are effective at reducing rates of complications, hospitalization, and mortality and the duration of illness. Additionally, the earlier NA inhibitors are provided, the better the outcome, though late administration can still be beneficial in severe cases. Other NA inhibitors include laninamivir and peramivir, the latter of which can be used as an alternative to oseltamivir for people who cannot tolerate or absorb it.The adamantanes amantadine and rimantadine are orally administered drugs that block the influenza viruss M2 ion channel, preventing viral uncoating. These drugs are only functional against IAV but are no longer recommended for use because of widespread resistance to them among IAVs. Adamantane resistance first emerged in H3N2 in 2003, becoming worldwide by 2008. Oseltamivir resistance is no longer widespread because the 2009 pandemic H1N1 strain (H1N1 pdm09), which is resistant to adamantanes, seemingly replaced resistant strains in circulation. Since the 2009 pandemic, oseltamivir resistance has mainly been observed in patients undergoing therapy, especially the immunocompromised and young children. Oseltamivir resistance is usually reported in H1N1, but has been reported in H3N2 and IBVs less commonly. Because of this, oseltamivir is recommended as the first drug of choice for immunocompetent people, whereas for the immunocompromised, oseltamivir is recommended against H3N2 and IBV and zanamivir against H1N1 pdm09. Zanamivir resistance is observed less frequently, and resistance to peramivir and baloxavir marboxil is possible. Prognosis
In healthy individuals, influenza infection is usually self-limiting and rarely fatal.
== References ==