Differential Efficacy of Clarithromycin in Lung versus Thigh Infection Models

Abstract
Background: Differences in clarithromycin disposition and the resulting changes in bacterial density were studied using mouse lung and thigh infection models. Methods: Clarithromycin activity was evaluated against seven Streptococcus pneumoniae isolates with efflux-mediated resistance in both murine lung and thigh infection models. Intrapulmonary disposition of clarithromycin was also studied. Results: Consistent bacterial kill was observed in the lung model, whereas no drug effect was observed in the thigh model. Conclusion: These differences in bacterial density were supported by high concentrations observed in epithelial lining fluid as compared to serum.