Bacteriologic and Clinical Response in Patients (Pts) with Acute Otitis Media (AOM): A Comparison between Amoxicillin/Clavulanate (A/C) and Azithromycin (AZ):

Abstract 930 Poster Session IV, Tuesday, 5/4 (poster 173) In a prospective, randomized, multi-national (sites: 8 US, 1 Israel, 1 Dominican Rep.), single-blind study conducted during the 1997-1998 winter season, 238 pts, aged 6-48 months, (median 13.2), with clinically confirmed diagnosis of acute otitis media (AOM), received either amoxicillin/clavulanate (A/C), 45 mg/kg/day in two divided doses for 10 days, or azithromycin (AZ), 10 mg/kg in a single dose on day 1 followed by 5 mg/kg q 24 hrs on days 2-5. Bacteriologic cultures from MEF were obtained by tympanocentesis at baseline and repeated at day 4, 5, or 6 if initial culture was positive for Haemophilus influenzae (HI) or Streptococcus pneumoniae (SP). 83 HI pts and 59 SP pts were evaluable for bacteriologic efficacy. Bacteriologic success (eradication of the initial pathogen from the MEF at day 4-5) for evaluable pts was as follows: (Table) Bacteriologic outcome with SP was not affected by penicillin- or A/C-susceptibility in either treatment group, but was associated with AZ resistance in AZ group [eradication in 11/13 (85%) AZ-susceptible vs. 2/6 (33%) AZ-resistant SP; p=0.011]. Clinical responses were 35/39 (90%) and 29/46 (63%) in HI-only pts for A/C and AZ respectively (p=0.0045). This study demonstrated that A/C was significantly superior to AZ in bacteriologic eradication of HI from MEF and in clinical response to infection with HI.