Factors Influencing the Effectiveness of Oseltamivir and Amantadine for the Treatment of Influenza: A Multicenter Study from Japan of the 2002--2003 Influenza Season

Early administration increases the benefit of anti-influenza drugs--not only the benefit of oseltamivir treatment for influenza A, but also the benefit of amantadine treatment for influenza A and oseltamivir treatment for influenza B. Oseltamivir may be less effective as a treatment for influenza B than for influenza A. A highest body temperature of > or = 39 degrees C was an indicator of a longer duration of fever.