[Studies on tissue concentrations of cefoperazone and piperacillin classified by the site of the wall of gallbladder and concentration of piperacillin in the bile after operation].

In selection of drugs to be used in the treatment of biliary tract infections, sensitivity of causative organisms to drugs and tissue concentrations of the drugs constitute important factors. In the present study we treated patients with cholelithiasis with cefoperazone (CPZ) and piperacillin (PIPC), both of which have been reported to show high concentrations in the bile, and concentrations of the drugs in serum, cholecystic bile and various sites of the wall of gallbladder were determined. In addition the drug concentrations in the serum and bile at the 1st and 7th postoperative days were also determined. The following results were obtained. Comparison of concentrations of CPZ and PIPC at various sites of the wall of gallbladder revealed that both drugs showed high levels in the bottom, body and neck areas of the gallbladder with no difference by sites. The concentration ratios against serum for these drugs were 71.8 and 83.6%, showing good transference into tissue. The mean concentrations of CPZ and PIPC in the cholecystic bile were as high as 448.8 and 381.6 micrograms/ml, the ratio against serum being about 4:1. The serum concentrations of PIPC at the 1st and 7th postoperative days were 116 and 137 micrograms/ml at 60 minutes after starting drip infusion, with no difference between these 2 days. In the bile concentrations of PIPC on both postoperative days showed the peak levels of 2,587 and 1,157 micrograms/ml at 120 minutes after starting drip infusion. The concentrations at the 1st postoperative day were higher. The recovery rate of PIPC from the bile was also higher at the 1st postoperative day. From the results that both drugs showed high levels in the wall of gallbladder and also showed high levels in the bile immediately after the operation, PIPC and CPZ are considered to be effective drugs for biliary tract infections.