Time-Course of the Concentration of Cefotiam in Human Extra-Vascular Pulmonary Tissue

: The concentration of cefotiam in the blood and in blood-free, extra-vascular pulmonary tissue (lung tissue) was determined and its transition into the lung tissue was observed. One gram of cefotiam was injected intravenously into 27 lobectomized cases of bronchogenic carcinoma at 30 (n = 8), 60 (n = 6), 120 (n = 7) and 180 minutes (n = 6) before thoracotomy. Informed consent was obtained from these patients before the study. Lung samples were collected from the resected lobe immediately after thoracotomy, and the blood samples were also collected. Drug concentrations of the lung and blood specimens were determined. The blood volume of the lung sample was determined according to the gravimetric method with hemoglobin as an index. The drug concentration in the lung tissue was determined by the difference of the concentration between blood and lung. The time-courses of lung tissue drug concentration and blood drug concentration were compared. The lung tissue drug concentration reached a peak at 30 minutes after intravenous injection and thereafter decreased gradually, reaching equilibrium at about 50% of the blood concentration. Thirty minutes after intravenous injection, the lung tissue drug concentration was higher than the blood concentration, suggesting a higher rate of transition of the drug from the blood to the lung tissue than vice versa.