Bacteriologic and clinical efficacy of amoxicillin/clavulanate vs. azithromycin in acute otitis media

Objectives. To compare the bacteriologic and clinical efficacy of amoxicillin/clavulanate and azithromycin in patients with acute otitis media (AOM), particularly the ability to eradicate the predominant AOM pathogens from middle ear fluid as assessed by mandatory second tympano-centesis. Methods. In this single blind study 238 infants and children with AOM were randomized to receive amoxicillin/clavulanate (45/6.4 mg/kg/day in two divided doses for 10 days) or azithromycin (10 mg/kg on Day 1, then 5 mg/kg daily on Days 2 through 5), Tympanocentesis was performed before the first dose and repeated on Day 4, 5 or 6. Clinical response was assessed at end of therapy between Days 12 and 14 and at follow up between Days 22 and 28. Results. Amoxicillin/clavulanate was significantly more likely to eradicate all bacterial pathogens [83% (54 of 65) vs, 49% (35 of 71), P = 0.001] and Haemophilus influenzae [87% (26 of 30) vs, 39% (13 of 33), P = 0.0001] from middle ear fluid than was azithromycin, Amoxicillin/clavulanate was also more likely to eradicate Streptococcus pneumoniae, but the difference was not statistically significant [90% (18 of 20) vs, 68% (3 of 19), P = 0.095], On Days 12 to 14, signs and symptoms were more likely to resolve completely or improve in all culture-positive patients [86% (60 of 70) vs, 70% (51 of 73), P = 0.023] and in those with H. influenzae infections [91% (30 of 33) vs. 65% (22 of 34), P = 0.010] who received amoxicillin/clavulanate compared with those who received azithromycin, Otherwise there were no significant differences between groups in clinical outcomes on Days 12 to 14 or at follow-up. Conclusions. Our findings indicate that amoxicillin/clavulanate has superior bacteriologic and clinical efficacy compared with azithromycin in children with AOM.