A study was carried out in 12 patients, divided into two groups of 6, to determine tissue levels of cefatrizine in lung (group I) and bronchial secretions (group II) following a single oral dose of 500 mg. In group I, specimens of blood and lung tissue were collected after 2 h from one subgroup of 3 patients and after 3 h from the other subgroup of 3. Average levels were 8.5 and 7.0 mcg/ml for blood and 1.2 and 1.4 mcg/ml for lung tissue respectively. In group II blood and bronchial secretion concentrations were evaluated at the 2nd, 3rd and 6th hours from administration. Average values were 9.1 and 7.7 mcg/ml in blood at 2h and 3h respectively, whereas the average bronchial secretion concentration at the 3rd hour was 10.4 mcg/ml in the first subgroup. In the second subgroup the mean level in blood collected at the 2nd hour was 8.9 mcg/ml, and 2.5 and 4.1 mcg/ml respectively in blood and bronchial secretions at the 6th hour. Cefatrizine levels in bronchial secretions were higher than those in blood at both the 3rd and the 6th hour from administration: this kinetic peculiarity of the drug will doubtless play an important role in the therapeutic efficacy of cefatrizine
