title: Effect of double dose oseltamivir on clinical and virological outcomes in children and adults admitted to hospital with severe influenza: double blind randomised controlled trial.
abstract: OBJECTIVE
  To investigate the validity of recommendations in treatment guidelines to use higher than approved doses of oseltamivir in patients with severe influenza.
  
  
  METHODS
  Double blind randomised trial.
  
  
  METHODS
  Thirteen hospitals in Indonesia, Singapore, Thailand, and Vietnam.
  
  
  METHODS
  Patients aged ≥ 1 year admitted to hospital with confirmed severe influenza.
  
  
  METHODS
  Oral oseltamivir at double dose (150 mg twice a day/paediatric equivalent) versus standard dose (75 mg twice a day/paediatric equivalent).
  
  
  METHODS
  Viral status according to reverse transcriptase polymerase chain reaction (RT-PCR) for influenza RNA in nasal and throat swabs on day five.
  
  
  RESULTS
  Of 326 patients (including 246 (75.5%) children aged <15), 165 and 161 were randomised to double or standard dose oseltamivir, respectively. Of these, 260 (79.8%) were infected with influenza virus A (133 (40.8%) with A/H3N2, 72 (22.1%) with A/H1N1-pdm09, 38 (11.7%) with seasonal A/H1N1, 17 (5.2%) with A/H5N1) and 53 (16.2%) with influenza virus B. A further 3.9% (13) were false positive by rapid antigen test (negative by RT-PCR and no rise in convalescent haemagglutination inhibition titers). Similar proportions of patients were negative for RT-PCR on day five of treatment: 115/159 (72.3%, 95% confidence interval 64.9% to 78.7%) double dose recipients versus 105/154 (68.2%, 60.5% to 75.0%) standard dose recipients; difference 4.2% (-5.9 to 14.2); P=0.42. No differences were found in clearance of virus in subgroup analyses by virus type/subtype, age, and duration of illness before randomisation. Mortality was similar: 12/165 (7.3%, 4.2% to 12.3%) in double dose recipients versus 9/161 (5.6%, 3.0% to 10.3%) in standard dose recipients. No differences were found between double and standard dose arms in median days on supplemental oxygen (3 (interquartile range 2-5) v 3.5 (2-7)), in intensive care (4.5 (3-6) v 5 (2-11), and on mechanical ventilation (2.5 (1-16) v 8 (1-16)), respectively. No important differences in tolerability were found.
  
  
  CONCLUSIONS
  There were no virological or clinical advantages with double dose oseltamivir compared with standard dose in patients with severe influenza admitted to hospital.
  
  
  BACKGROUND
  Clinical Trials NCT00298233.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage; D002648:Child; D002985:Clinical Protocols / Q000592:standards; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006385:Hemagglutination Inhibition Tests / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007214:Indonesia; D007223:Infant; D009980:Influenza A virus / Q000145:classification / Q000187:drug effects / Q000502:physiology; D009981:Influenza B virus / Q000187:drug effects / Q000502:physiology; D007251:Influenza, Human / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology / Q000821:virology; D008875:Middle Aged; D053139:Oseltamivir / Q000008:administration & dosage*; D017410:Practice Guidelines as Topic; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D012846:Singapore; D013785:Thailand; D016896:Treatment Outcome; D014744:Vietnam
chemical_list: D000998:Antiviral Agents; D053139:Oseltamivir