Excretion and re-excretion of a broad-spectrum penicillin in bile.

A technique is described for estimating the biliary excretion, reabsorption and re-excretion of an antibacterial drug in rats. D(-)-6-(alpha-Amino-alpha-phenylacetamido)-penicillanic acid (BRL 1341) is rapidly excreted and re-excreted in the bile, in concentrations bactericidal to Salmonellae and other organisms which are usually refractory to antibacterial drugs in this situation. Recoveries of the drug accounted for 20 to 30% of oral of parenteral doses; much of the remainder is probably destroyed in the gut. Results from one patient indicate that D(-)-6-(alpha-amino-alpha-phenylacetamido)-penicillanic acid is excreted in high concentration also in human bile.