Zanamivir for treatment of symptomatic influenza A and B infection in children five to twelve years of age: a randomized controlled trial.
BACKGROUND
Influenza infection rates are higher in children than in other age groups. This study evaluated the efficacy, safety and tolerability of a 5-day course of twice daily inhaled zanamivir, 10 mg, compared with placebo in the treatment of symptomatic influenza A and B viral infections among children 5 to 12 years of age.


METHODS
This double blind, randomized, placebo-controlled, parallel group, multicenter study conducted in the Northern Hemisphere during the 1998 and 1999 influenza season enrolled 471 patients with influenza-like symptoms for < or = 36 h. Patients were randomly assigned to zanamivir (n = 224) or placebo (n = 247). Symptoms were recorded on diary cards twice daily during treatment, for 9 days after treatment and for 14 additional days (if still reporting moderate/severe cough and/or taking relief medication).


RESULTS
A total of 346 (73%) patients were influenza-positive by culture, serology or polymerase chain reaction (65% influenza A, 35% influenza B). Zanamivir reduced the median time to symptom alleviation by 1.25 days compared with placebo among patients with confirmed influenza infection (P < 0.001). Zanamivir-treated patients returned to normal activities significantly faster and took significantly fewer relief medications than placebo-treated patients. Zanamivir was well-tolerated, demonstrating adverse event profiles similar to those of placebo and no clinically significant changes in laboratory findings. Viral susceptibility testing revealed no zanamivir-resistant strains of influenza A or B.


CONCLUSIONS
Zanamivir was effective in shortening the duration and severity of influenza symptoms and was well-tolerated among children 5 to 12 years of age.
Hedrick
J A
JA
Kentucky Pediatric Research/Adult Unit, Bardstown, USA.
Barzilai
A
A
Behre
U
U
Henderson
F W
FW
Hammond
J
J
Reilly
L
L
Keene
O
O
D000280:Administration, Inhalation; D000998:Antiviral Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D006146:Guanidines; D006801:Humans; D009980:Influenza A virus / Q000187:drug effects / Q000302:isolation & purification*; D009981:Influenza B virus / Q000187:drug effects / Q000302:isolation & purification*; D007251:Influenza, Human / Q000188:drug therapy* / Q000821:virology; D008297:Male; D010349:Patient Compliance / Q000706:statistics & numerical data; D011714:Pyrans; D012794:Sialic Acids / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D053243:Zanamivir
D000998:Antiviral Agents; D006146:Guanidines; D011714:Pyrans; D012794:Sialic Acids; D053243:Zanamivir