Pivampicillin and ampicillin in bile, portal and peripheral blood.

In 7 patients with a catheter in the portal vein and a T tube in the common bile duct, the concentration of unhydrolyzed pivampicillin and of ampicillin was measured simultaneously in portal and peripheral blood and in bile after oral administration of 700 mg pivampicillin. In both portal and peripheral circulation of concentration of unhydrolyzed pivampicillin was always less than 1% of the levels of ampicillin, indicating the effectiveness of the intestinal mucosa in the hydrolysis of pivampicillin. Evidence for the ability of the liver to excrete ampicillin against a concentration gradient into the bile was established by direct measurements. Only about 1% of the dose given could be recovered in the bile. There was an unexplained reduction of about 70% in the absorption of the drug induced by the catheter itself.