[The serum and uterine muscle concentrations of Cephradin and Cephalothin]

On the day of operation 2 grams of Cephradin was given intravenously to 33 patient and 2 grams of Cephalothin was given intravenously to 31 patients. At various time intervals, uterine tissue and serum was removed. The mean serum concentrations of Cephradin were 3 times higher and the mean tissue concentrations of Cephradin were 7-8 times higher than the corresponding concentrations of Cephalothin. Because of the difference in protein binding of the examined cephalosporins (Cephradin 6%, Cephalothin 60-65%) the difference for the antimicrobially active portion (Protein free portion) is even more favorable for Cephradin. The significance of these pharmacokinetic differences for the treatment are obvious.