Computer simulation of ciprofloxacin pharmacokinetics in patients on CAPD

Continuous ambulatory peritoneal dialysis (CAPD) has become an accepted alternative to chronic hemodialysis in the treatment of end-stage renal disease. The method utilizes the diffusion of drugs from the blood through the peritoneal membrane to the peritoneal cavity if administered intravenously (IV) and perorally (PO) and in the opposite direction if applied intraperitoneally (IP). The present work uses an open, two-compartment pharmacokinetic model reversibly linked with the compartment representing the peritoneal cavity and an analog-hybrid computer to simulate drug levels in sampled and unsampled compartments under conditions of various routes of administration (IV, IP and sequential IV, IP and PO) and different clinical status (presence and absence of peritonitis). The drug chosen for simulation was ciprofloxacin (CIP), a new synthetic antibacterial agent of the 4-quinolone group. Eight patients were included in the study, and CIP concentrations in plasma and dialysate were obtained by HPLC analysis to assess the reliability of the model and the efficiency of the sequential dosing scheme. CIP plasma and dialysate levels were adequate for the majority of microbes causing CAPD peritonitis. The proposed regimen was efficient in 85% of cases.