A comparison of the effectiveness of zanamivir and oseltamivir for the treatment of influenza A and B.
OBJECTIVE
To compare the effectiveness of zanamivir with oseltamivir for influenza A and B.


METHODS
1113 patients with influenza A or B were enrolled in the 2006-2007 influenza season. The duration of fever (temperature, >or=37.5 degrees C) and the percentage of patients afebrile at 24 and 48 h after the first dose of zanamivir or oseltamivir were calculated. Virus persistence after zanamivir therapy was also evaluated.


RESULTS
There were marginally significant differences between the duration of fever after the first dose of zanamivir (31.8+/-18.4h) and oseltamivir (35.5+/-23.9h) for influenza A (p<0.05). The duration of fever after starting zanamivir therapy (35.8+/-22.4h) was significantly shorter than that of oseltamivir (52.7+/-31.3h) for influenza B (p<0.001). There were no significant differences between influenza A and B in the percentage of patients afebrile at 24 or 48 h after the first inhalation of zanamivir. The reisolation rate after zanamivir therapy showed marginally significant differences between influenza A and B (<0.05). By multiple regression analysis, therapy (zanamivir or oseltamivir) was the major determinant affecting the duration of fever for influenza B.


CONCLUSIONS
Zanamivir therapy is more effective than oseltamivir for the treatment of influenza B infection.
Kawai
Naoki
N
Japan Physicians Association, Tokyo Medical Association Building 3F, 2-5 Kanda-Surugadai, Chiyoda-ku, 101-0062 Tokyo, Japan. nkawai@city.gifu.med.or.jp
Ikematsu
Hideyuki
H
Iwaki
Norio
N
Maeda
Tetsunari
T
Kanazawa
Hideo
H
Kawashima
Takashi
T
Tanaka
Osame
O
Yamauchi
Satoshi
S
Kawamura
Kenichi
K
Nagai
Toru
T
Horii
Satsuki
S
Hirotsu
Nobuo
N
Kashiwagi
Seizaburo
S
D000280:Administration, Inhalation; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D005260:Female; D005334:Fever / Q000473:pathology; D006801:Humans; D009980:Influenza A virus; D009981:Influenza B virus; D007251:Influenza, Human / Q000188:drug therapy* / Q000473:pathology / Q000821:virology; D007564:Japan; D008297:Male; D053139:Oseltamivir / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome; D053243:Zanamivir / Q000008:administration & dosage / Q000627:therapeutic use*
D053139:Oseltamivir; D053243:Zanamivir