Comparative penetration of selected fluoroquinolones into respiratory tract fluids and tissues

Sputum samples are easy to obtain; however, their use in therapeutic decision making is not without problems. Today, with the availability of more sophisticated endoscopic procedures, it is possible to determine antimicrobial concentrations at various sites within the respiratory tract. Fiber-optic bronchoscopy makes it possible to obtain samples of bronchial mucosa, bronchial epithelial lining fluid (ELF), and alveolar macrophages (AMs). Antimicrobial concentration measurements from the bronchial mucosa, ELF, and AM may be better predictors of successful antimicrobial therapy than sputum samples. In general, fluoroquinolones penetrate well into lung tissue, including bronchial mucosa, ELF, and AM, resulting in concentrations higher than corresponding serum levels. Temafloxacin, a new fluoroquinolone, attains high bronchial concentrations that are well above the 90% minimal inhibitory concentration (MIC90) for many of the common respiratory pathogens, including Streptococcus pneumoniae (MIC90 = 0.5 micrograms/mL). Early clinical trials confirm the clinical efficacy and safety of temafloxacin in the treatment of many common respiratory tract infections. The penetration of temafloxacin into the bronchial mucosa, AM, and ELF along with its antimicrobial spectrum supports the use of temafloxacin against common respiratory pathogens, including S. pneumoniae.