Treatment of ampicillin-resistant acute otitis media in the chinchilla.

The efficacy of sulbactam sodium (CP45,899-2) was investigated using the chinchilla animal model of acute otitis media with effusion (AOME). Both ears of 78 chinchillas were inoculated with beta-lactamase-producing nontypable Hemophilus influenzae. Half of the animals were treated with ampicillin sodium alone (group A) and the remaining animals received ampicillin plus sulbactam (group B). On day 14, all of the ears in group B were culture-negative whereas H influenzae was recoverable in over 70% of the effusions in group A. Similarly, the course of middle ear effusion was significantly abbreviated in group B during the two-week study period. These findings suggest that sulbactam in combination with ampicillin is effective in treating AOME secondary to infection with beta-lactamase-producing nontypable H influenzae in the chinchilla animal model.