Pharmacokinetic study of rifampicin in biliary surgery.

Following the oral administration of 600 mg rifampicin, the concentration of antibiotic in serum, bile of the gallbladder and choledochus, cholecystic wall, and hepatic tissue was determined with the agar diffusion method in 23 patients undergoing surgery for cholelithiasis. After 80-340 minutes the average rifampicin concentration was 6.4 microgram/ml in serum, 78.4 microgram/ml in the bile of the gallbladder, 91.6 microgram/ml in the bile of the choledochus, 4.0 microgram/g in the cholecystic wall, and 23.3 microgram/g in the hepatic tissue. After 24 hours the level was significantly reduced in the serum and hepatic tissue. The rifampicin level in the bile of the gallbladder was twelvefold, in the bile of the choledochus fourteenfold, in the cholecystic wall 61.1% and in the hepatic tissue 364% of the serum level. In general, the rifampicin concentration obtainable in the bile and hepatic tissue is sufficient against bacterial strains causing infections of the biliary duct, and for this reason rifampicin will play in the future an important role in the treatment of infections of the biliary duct.