The duration of fever and other symptoms after the initiation of laninamivir octanoate hydrate in the Japanese 2011-2012 influenza season.
Laninamivir octanoate hydrate (laninamivir) is a long-acting, single inhalation neuraminidase inhibitor that was approved in Japan in 2010 for the treatment of influenza A and B virus infection. We investigated the duration of fever and other symptoms after the initiation of laninamivir in the Japanese 2011-2012 influenza season. Virus isolation was done and the 50% inhibitory concentration (IC₅₀) was measured for the virus isolates at days 1 and 5. For 211 patients (A(H3N2): 190, B: 21), the median durations of fever of A(H3N2) and B patients were 33.0 and 50.0 h, respectively (p = 0.0989). Fever was resolved within 72 h after inhalation by 89.7% of the A(H3N2) patients and by 81.0% of the patients with B. The median durations of symptoms for A(H3N2) and B patients were 89.0 and 94.0 h, respectively (p = 0.5809). On day 5, the influenza virus-positive rates for A(H3N2) and B patients were significantly different: 25.8% (40/155) and 70.6% (12/17), respectively (p < 0.0001). No significant change in IC₅₀ value was found between day 1 and day 5 for any of the four tested neuraminidase inhibitors, and no IC₅₀ value exceeded 50 nM. The incidence of adverse drug reactions was 1.3% (3/234), with no serious reactions reported. These results show that laninamivir was effective for the treatment of both influenza A(H3N2) and B in this study, with no safety issues. The clinical effectiveness of laninamivir for A(H3N2) was superior to that for B.
Department of Clinical Trials, Center for Advanced Medical Innovation, Kyushu University, Japan; Japan Physicians Association, Tokyo, Japan. Electronic address: hikematsu@camiku.kyushu-u.ac.jp.
Hideyuki
H
Ikematsu
Japan Physicians Association, Tokyo, Japan.
Naoki
N
Kawai
Japan Physicians Association, Tokyo, Japan.
Norio
N
Iwaki
Japan Physicians Association, Tokyo, Japan.
Seizaburo
S
Kashiwagi
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005334:Fever / Q000821:virology*; D006146:Guanidines; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects / Q000302:isolation & purification*; D009981:Influenza B virus / Q000187:drug effects / Q000302:isolation & purification*; D007251:Influenza, Human / Q000188:drug therapy* / Q000503:physiopathology* / Q000821:virology; D020128:Inhibitory Concentration 50; D008297:Male; D008875:Middle Aged; D011714:Pyrans; D012794:Sialic Acids; D055815:Young Adult; D053243:Zanamivir / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use
D000998:Antiviral Agents; D006146:Guanidines; D011714:Pyrans; D012794:Sialic Acids; C546918:laninamivir; D053243:Zanamivir
Efficacy; IC(50); Laninamivir; Long-acting neuraminidase inhibitor