Rifampicin concentrations in bronchial mucosa, epithelial lining fluid, alveolar macrophages and serum following a single 600 mg oral dose in patients undergoing fibre-optic bronchoscopy

The concentrations of rifampicin in epithelial lining fluid (ELF), human alveolar macrophages (AM), bronchial mucosal biopsies and serum were measured after a single oral dose of 600 mg rifampicin from 15 patients undergoing fibre-optic bronchoscopy. The samples of ELF, AM, the bronchial mucosal biopsies and serum were obtained ∼2–5 h after dosing. The mean concentrations (mean ± standard error) were 5.25 mg/L (±0.67) in ELF, 7.93 mg/kg (±1.61) in bronchial biopsies, 15.48 mg/L (±1.41) in serum and 251.8 mg/L (±65.92) in alveolar macrophages. These site concentrations exceeded the MIC90 for common respiratory pathogens including Mycobacterium tuberculosis and support the observed clinical efficacy of rifampicin in the treatment of a wide range of respiratory tract infections.