Gentamicin and Ampicillin in Human Bile

Concentrations of antibiotic in bile were measured following the administration of intramuscular gentamicin to five patients and intravenous ampicillin to one. Biliary gentamicin excretion by four individuals with abnormal hepatic function was minimal. Gentamicin levels in the bile of one patient with essentially normal hepatic function were 33 % and 88 % of those in serum. Intravenous ampicillin yielded high peak values in the bile and serum of one person with deranged hepatic function. The penetration of antibiotic into bile may be necessary for successful eradication of hepato-biliary infection [1]. We shall present simultane-ous concentrations of gentamicin and ampicillin in bile and serum from individuals with infection following surgery of the biliary tract. Materials and Methods Patients were studied after T-tube drainage had been established from a patent common bile duct. Each had fever, leukocytosis, and cultures of bile that yielded gram-negative bacilli with resistance to multiple antibiotics. Ampicillin and gentamicin were administered together to four patients and sequentially to one. The dose of gentamicin for those patients with normal renal function was 3-5 rug/kg per day. Samples of bile and serum were collected simultaneously at intervals follow-ing either intravenous ampicillin or intramuscular gentamicin. Bile was sterilized by passage through a 0.45-1-! Millipore filter, frozen at-20 C, and mailed in dry ice to Schering Laboratories, Bloom-field, New Jersey, for assay of gentamicin. Th