Efficacy of Antibiotics

Contact: Porter Novelli, Michelle Ertischek (212) 601-8250, mertischek@porternovelli.com
Rhea Juntereal (212) 601-8123, rjuntereal@porternovelli.com

STUDY EXAMINES EFFICACY OF ANTIBIOTICS IN ACUTE OTITIS MEDIA

(Dallas, TX, September 25, 1998) -- In a comparison study between two antibiotics that will be presented at the 38th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in San Diego, CA, researchers show that treatment of children's middle ear infections with amoxicillin/clavulanate reduced colonization by Streptococcus pneumoniae in the nasopharynx by nearly 66 percent. In comparison, treatment with the antibiotic, azithromycin, reduced S. pneumoniae carriage by approximately 25 percent. Carriage of Haemophilus influenzae was also reduced more effectively by amoxicillin/clavulanate treatment.

The bacteria S. pneumoniae and H. influenzae cause middle ear infection and sinus infections that are commonly seen in the doctor's office.

Among the initial findings, the researchers determined that 63 percent of

S. pneumoniae isolates were resistant to penicillin and 55 percent to azithromycin before treatment. There appeared to be no differences among these patients with regard to the clinical response to therapy of the acute otitis media episodes.

"Our results indicate that amoxicillin/clavulanate is effective at eradicating all but the most penicillin-resistant strains of Streptococcus pneumoniae," said George H. McCracken, Jr., M.D., professor of pediatrics, Sarah M. and Charles E. Seay Chair in Pediatric Infectious Diseases, Southwestern Medical School, Dallas.

Results showed that amoxicillin/clavulanate eradicated or suppressed strains of S. pneumoniae that were penicillin-susceptible. Azithromycin did not eradicate one-third of strains that were identified as susceptible to azithromycin. This suggests that concentrations of this drug in the nasopharyngeal secretions maybe low relative to the MIC of the organism.

The investigators sought to determine the effect of the antibiotics amoxicillin/clavulanate and azithromycin on the carriage of S. pneumoniae and

H. influenzae bacteria in the nasopharynx of children aged 6 months to 6 years. Researchers cultured the nasal passages of children before treatment and two weeks following (5-10 days after completing treatment). As of September, 1, 1998, the researchers have completed follow-up of 140 children.

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