Cefepime is a broad-spectrum antibiotic used in treating CAPD peritonitis. However, medical knowledge has been lacking with regard to its pharmacokinetic profile after it has been administered intraperitoneally. The current study aims at determining the drug level at different time after the drug has been added into the peritoneal fluid in patients with CAPD peritonitis. The results of this study will finally leads to rational prescription of this drug at correct dosages.