Q: Why Daptomycin is a bad choice for use in Pneumonia?
Answer: Daptomycin is a bad choice in the treatment of respiratory tract infections because surfactant in lungs binds daptomycin, leaving free drug concentrations in pulmonary secretions to very minimal. This is the only known organ-specific inhibition of an antibiotic.
Inhibition of daptomycin by pulmonary surfactant: in vitro modeling and clinical impact. - J Infect Dis. 2005 Jun 15;191(12):2149-52.