[Competitive in vitro binding of bilirubin and ceftizoxime to human serum albumin (author's transl)].

The competitive effect of ceftizoxime, a new cephalosporin, on in vitro binding of bilirubin to human serum albumin was investigated and compared with that of other beta-lactam antibiotics. At the normal range of the albumin (3.48 g/dl) and bilirubin (0.936 mg/dl) concentrations in the serum of healthy infants, free bilirubin concentration was not increased by adding ceftizoxime and the other beta-lactam antibiotic concentrations tested (up to 640 micrograms/ml). The same results were obtained even under the same condition except that the bilirubin concentration was increased to 10 mg/dl. Under the condition that the albumin concentration decreased to one fifth of the normal concentration, bilirubin was competitively displaced to some extent by adding dicloxacillin (MDIPC), cefazolin (CEZ) and cefmetazole (CMZ) but not by adding ceftizoxime at the concentration of 640 micrograms/ml.