Serum and sputum concentrations of cefoxitin were measured at fixed intervals following a one hour drip infusion of 2 g to a total of three patients with chronic respiratory tract diseases. The peak levels in serum were found to be 142.1-273.6 microgram/ml at the end of the infusion and those in sputum were found to be 0.92-2.30 microgram/ml at 2 to 4 hours after initiation of the infusion. 2. Cefoxitin was administered to a total of five patients with chronic respiratory tract infections who had failed to respond to the previous treatments with conventional antibiotics. The results were that in one case the therapeutic effect was judged as excellent, in three cases as good, and in one case it was difficult to evaluate. In all cases, there was no significant abnormality indicative of side effects regarding clinical symptoms and laboratory tests of renal and hepatic functions. In a view of the findings stated above, it is considered that cefoxitin is a new antibiotic which can be used for the treatment of chronic respiratory tract infections.
