Our objective was to compare the clinical efficacy of azithromycin vs. erythromycin and
amoxicillin in the treatment of presumed bacterial community-acquired pneumonia in ambulatory
children, and to evaluate the etiologies of these illnesses. One hundred and ten children, aged 1
month to 14 years, were enrolled between January 1996–January 1999. Children were distributed
into two groups according to clinical and radiological patterns: classic or atypical pneumonia.
Patients with classic pneumonia were randomly assigned to receive oral amoxicillin 75 mg/kg/day
for 7 days, or azithromycin 10 mg/kg/day for 3 days; patients with atypical pneumonia received
azithromycin 10 mg/kg/day for 3 days, or erythromycin 50 mg/kg/day for 14 days. Chest X-ray,
clinical, and laboratory parameters were obtained on enrollment. Clinic visits were performed on
days 3, 7, and 14, and chest X-ray follow-up on days 7 and 14. Microbiological diagnosis of classic
pathogens was based on blood and bronchial secretion cultures. The diagnosis of atypical
pathogens C. pneumoniae, C. trachomatis, and M. pneumoniae was based on PCR and serologic
tests.
Forty-seven children met the criteria for classic pneumonia (23 children received azithromycin,
and 24 received amoxicillin), and 59 children had atypical pneumonia (33 children were treated
with azithromycin, and 26 with erythromycin). Demographic characteristics at enrollment were
similar between children with classic pneumonia treated with azithromycin and erythromycin and
children treated with azithromycin and erythromycin for atypical pneumonia. However, on day 7,
children with classic pneumonia who received azithromycin normalized their chest X-ray more
often than those who received amoxicillin (81.0% vs. 60.9%, respectively, P ¼ 0.009). The same
was true for children with atypical pneumonia; their chest X-rays had normalized by day 14 (100% in
those with azithromycin vs. 81% in those with erythromycin, P ¼ 0.059). Also, children with atypical
pneumonia treated with azithromycin had earlier cessation of cough than children treated with
erythromycin (3.6 1.9 vs. 5.5 3.6 days respectively, P ¼ 0.02). There were only three children
with side effects (mild diarrhea, all in the erythromycin group). Etiological agents were identified in
41% of children.
In conclusion, azithromycin is an effective therapeutic option for the treatment of communityacquired classic and atypical pneumonia in children.