Pulmonary disposition of moxalactam.

Moxalactam is a new synthetic oxa-beta-lactam antibiotic with a broad spectrum of activity against Gram-positive and Gram-negative aerobic and anaerobic bacteria. It has proven clinical efficacy in pneumonia caused by a variety of infecting organisms. Therapeutic concentrations of moxalactam are achieved in most body tissues and fluids, including pleural fluid and sputum. However, assessment of the adequacy of lung tissue levels in pneumonia requires the sampling of material at an alveolar level. We performed bronchoalveolar lavage (BAL) in 13 patients one hour after they had been given moxalactam intravenously in doses ranging from 250 mg to 2 g. Absolute alveolar drug levels ranged from less than 1 to 6 micrograms/ml, and serum levels from 8 to 50 micrograms/ml. When expressed per micromole of creatinine, there was a significant relationship (r = 0.85; p less than 0.01) between serum and alveolar moxalactam levels in those patients in whom the drug concentration could be quantified accurately in BAL fluid.