Biliary elimination of ceftazidime.

Area of Science:

• Pharmacology
• Gastroenterology
• Infectious Diseases

Background:

• Ceftazidime is a third-generation cephalosporin antibiotic.
• Understanding antibiotic penetration into biliary and duodenal fluids is crucial for treating infections in these areas.

Purpose of the Study:

• To quantify ceftazidime concentrations in human duodenal fluid and bile following intravenous administration.
• To assess the potential therapeutic levels of ceftazidime in the biliary tract and upper gastrointestinal fluid.

Main Methods:

• Intravenous administration of ceftazidime (2 g) to normal subjects and patients with external biliary drains.
• Aspiration of duodenal fluid and collection of bile for concentration analysis.
• Peroperative sampling of choledochal and gallbladder bile.

Main Results:

• In normal subjects, ceftazidime concentrations in duodenal fluid reached 21.2 mg/l, with 0.05% of the dose recovered.
• In patients with biliary drains, peak ceftazidime concentrations in bile were 36.3 mg/l, with 0.21% of the dose recovered over 12 hours.
• Peroperative bile samples showed high concentrations: 78.3 mg/l in choledochal bile and 17.9 mg/l in gallbladder bile.

Conclusions:

• Intravenous ceftazidime achieves significant concentrations in duodenal fluid and bile.
• The observed levels suggest favorable penetration and potential efficacy for treating infections involving the biliary system and upper GI tract.
• Ceftazidime's pharmacokinetic profile in these fluids compares well with other beta-lactam antibiotics.