Concentration behavior of carbamazepine in bile and plasma of man.

The concentration in plasma and bile of carbamazepine was determined in four humans with Kerr's T-tube drain after an oral administration of a single dose of 400 mg of Finlepsin (carbamazepine). The mean plasma half-life time was 25 (15-31) hr. The concentration time curves in bile and plasma were parallel with the bile to plasma concentration ratio of 0.62 (0.24-0.82). A negative linear correlation between the lithogenic index and the bile plasma concentration ratio was found. It is suggested that the concentration of carbamazepine in bile is influenced by the saturation of biliary micelles with cholesterol. The amount of carbamazepine eliminated by bile within 72 hr was 4.1 +/- 1.9 mg, i.e., 1% of the administered dose. It is concluded that there is no significant enterohepatic circulation of carbamazepine.