title: Once-daily amoxicillin versus twice-daily penicillin V in group A beta-haemolytic streptococcal pharyngitis.
abstract: BACKGROUND
  Rheumatic fever is a preventable chronic disease preceded by group A beta-haemolytic streptococcal (GABHS) pharyngitis.
  
  
  OBJECTIVE
  To test the non-inferiority of once-daily (QD) oral amoxicillin to the recommended twice-daily (BID) oral penicillin V in GABHS pharyngitis.
  
  
  METHODS
  This was a randomised non-inferiority trial carried out in a school-based clinic in New Zealand. Children presenting with GABHS pharyngitis were randomised to oral amoxicillin 1500 mg QD (or 750 mg if bodyweight was <or=30 kg) or to oral penicillin V 500 mg BID (or 250 mg if bodyweight was <or=20 kg) for 10 days. Observed medication and weekend diary cards were used to monitor adherence.
  
  
  RESULTS
  Eradication of GABHS, determined with follow-up throat cultures on days 3-6, 12-16 and 26-36. GABHS isolates were serotyped to distinguish bacteriological treatment failures (and relapses) from new acquisitions. Non-inferiority was defined as an upper 95% confidence limit (CL) for the difference in success of eradication in the amoxicillin and penicillin V treatment groups of <or=10%.
  
  
  RESULTS
  353 children with positive throat swabs for GABHS were randomised to amoxicillin (n = 177) or penicillin V (n = 176). The upper 95% CL for the differences in positive cultures between the antibiotics was 4.9% at days 3-6, 6.5% at days 12-16 and 8.5% at days 26-36. Treatment failures (including relapses) occurred at each visit in 5.8%, 12.7% and 10.7% of amoxicillin recipients and 6.2%, 11.9% and 11.3% of penicillin V recipients, respectively. No significant differences in resolution of symptoms were noted between treatment groups. One case of unsubstantiated acute rheumatic fever occurred after 7 days of amoxicillin.
  
  
  CONCLUSIONS
  In this adequately powered study, once-daily oral amoxicillin is not inferior to twice-daily penicillin V for the treatment and eradication of GABHS in children with pharyngitis.
authors.affiliation: Department of Paediatrics, University of Auckland, Private Bag 92019, Auckland, New Zealand. d.lennon@auckland.ac.nz
authors.forename: D R
authors.initials: DR
authors.lastname: Lennon
authors.forename: E
authors.initials: E
authors.lastname: Farrell
authors.forename: D R
authors.initials: DR
authors.lastname: Martin
authors.forename: J M
authors.initials: JM
authors.lastname: Stewart
mesh_terms: D000208:Acute Disease; D000658:Amoxicillin / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D009520:New Zealand; D010404:Penicillin V / Q000008:administration & dosage*; D010612:Pharyngitis / Q000188:drug therapy* / Q000382:microbiology; D012213:Rheumatic Fever / Q000188:drug therapy / Q000517:prevention & control*; D013290:Streptococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D000658:Amoxicillin; D010404:Penicillin V