[Distribution of an antibiotic (cefotiam) to the breast tissue]

In order to demonstrate the distribution of an antibiotic to normal breast tissues and its penetration into the axillary wound exudate, 1 g of a new cephem antibiotic, cefotiam (CTM), was infused intravenously over 1 hour in 14 patients with breast cancer before and after mastectomy. CTM concentrations were assayed by the cylinder-plate method, using Proteus mirabilis ATCC 21100 as the test organism. Overall CTM levels in the normal breast tissues ranged from 3.6 to 27.7 micrograms/g, and 5.2 micrograms/g of CTM still remained 170 minutes after administration. No significant differences were found in CTM levels of 3 parts of the breast tissue from the same patient. Serum CTM levels rapidly declined after the end of infusion of CTM. Concentrations of CTM in axillary wound exudate after mastectomy ranged from 5.2 to 13.6 micrograms/ml at 3 hours after administration and were almost undetectable at 24 hours. It is concluded that CTM levels in breast tissues were almost the same as those in other tissues.