PENETRATION OF CLOARITHROMYCIN INTO LUNG TISSUES FROM PATIENTS UNDERGOING LUNG RESECTION

The concentrations of clarithromycin and its active principal metaboli te, 14-(R)-hydroxy-clarithromycin, were determined in lung tissue obta ined during lung resection and compared with concomitant concentration s in plasma. Concentrations of the parent and metabolite were determin ed by high-performance liquid chromatography. The 15 patients studied were given 500 mg orally every 12 h for a minimum of five doses to ach ieve steady-state concentrations. The mean concentrations of clarithro mycin and 14-(R)-hydroxy-clarithromycin in plasma just prior to the fi nal dose were 1.38 and 0.67 mug/ml, respectively, and those 4 h after the final dose (at the time of lung resection) were 1.89 and 0.80 mug/ mL, respectively. The concentrations of the parent and metabolite in l ung tissue at the time of lung resection averaged 54.3 and 5.12 mug/g, respectively, with a mean calculated ratio of concentrations of the p arent to metabolite being 11.3 in lung tissue and 2.4 in plasma. Clari thromycin and its active metabolite are extensively distributed into h uman lung tissue.