Pharmacokinetics and pharmacodynamics of new and old antimicrobial agents for acute otitis media

Selection of appropriate antibiotic treatment for children with acute otitis media (AOM) is challenging. Although the diagnosis is relatively easy for experienced clinicians, the distinction between AOM and otitis media with effusion is often more subtle. In general therapy is empiric and the pathogen causing disease in a given patient remains unknown. However, this situation is made even more difficult by the dynamic nature of the pathogenesis of AOM. Both the proportion of patients infected with one of the three primary pathogens, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, and the antimicrobial susceptibility patterns of these pathogens are changing. Currently there are 16 antibiotics labeled for use in AOM. Only 2 are reliably effective against penicillin-resistant pneumococcus: high dose amoxicillin (80 to 100 mg/kg/day) and im ceftriaxone. Among the others all are beta-lactamase-stable and have proven clinical effectiveness in AOM patients infected with H. influenzae or M. catarrhalis. Even with the high spontaneous resolution rate reported for AOM, antimicrobial therapy remains the standard of care in the United States. Recognition of the fundamental determinants of effective therapy should permit rational antibiotic selection for each patient.