Cephalothin sodium levels in serum, gallbladder bile, gallbladder tissue, and common duct bile were studied in both normal patients and patients with biliary disease. The results show that cephalothin is concentrated in bile in normal patients and patients with gallbladder disease. In the presence of jaundice, results are less conclusive. Following a single dose of the drug, peak level in bile was reached at two hours; the level at eight hours was less than 1μg/ml in patients with biliary drainage through a T tube in the common bile duct.
Since the antibacterial spectrum of cephalothin includes a large number of common biliary pathogens, and since the concentration of the drug in bile reaches levels higher than the minimal inhibitory and even bactericidal concentration in the absence of obstructive jaundice, it could be of value in the treatment of biliary infections.
Ram MD, Watanatittan S. Cephalothin Levels in Human Bile. Arch Surg. 1974;108(2):187-189. doi:10.1001/archsurg.1974.01350260043009