[Current anti-influenza virus chemotherapy].

The environment surrounding influenza is changing in recent years. In the spring of 2009, pandemic (H1N1) 2009 occurred in Mexico, and became epidemic on a global scale thereafter. Therefore, control of influenza is very important all over the world. Now in Japan, four specific anti-influenza antiviral drugs are available: amantadine, oseltamivir, zanamivir and peramivir. Pandemic (H1N1) 2009 are amantadine-resistant viruses, thus is not recommended for use. Oseltamivir is most commonly used in Japan, however, we have to pay attention to oseltamivir-resistant influenza virus. Almost no zanamivir-resistant influenza virus has been so far reported. In Japan, peramivir is the first drip infusion medicine and is expected to be used in severe cases.