Laninamivir octanoate hydrate (
laninamivir) is a long-acting
neuraminidase inhibitor which requires only a single inhaled dose to fully treat
infection by the influenza virus. In Japan, this
drug was launched in October 2010 as a new treatment for the influenza virus. A postmarketing surveillance study was conducted in the 2010/2011
influenza season to assess the efficacy of this
drug in clinical settings. For 3542 patients evaluated for efficacy (type A, n = 3179; type B, n = 342, unknown type, n = 3), including the day of
drug administration, the median duration to
fever resolution was three days, and the median duration to relief from
influenza symptoms was four days. Based on the judgment of participating physicians, the efficacy rate was 97.6 % for type A
influenza, 93.3 % for type B
influenza, and 100 % in unknown types. "Treatment failure," as judged by participating physicians, was most closely correlated with the inhalation status of
laninamivir. Despite
laninamivir requiring only the administration of a single dose, it was confirmed to be an effective treatment in more than 90 % of patients with type A or type B influenza virus
infections. This
drug was considered to be useful for the treatment of
influenza infections due to ease of use and its improvement of compliance. It became clear that the efficacy of
laninamivir depended strongly on the status of inhalation, and thus careful and detailed instructions on the correct method of inhalation were considered to be important in order to obtain reliable
therapeutic effects.