Ciprofloxacin in plasma and peritoneal dialysate after oral therapy in patients on continuous ambulatory peritoneal dialysis

The quinolone antibiotic ciprofloxacin offers the possibility of effective oral treatment of peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD) if a sufficiently high concentration is attained in peritoneal dialysate. The pharmacokinetics of oral ciprofloxacin have been studied in ten CAPD patients given 250 mg qds for two days. Five patients were being treated for peritonitis with gentamicin and cefuroxime; the remaining five were receiving inpatient training for CAPD or were being treated for other problems. Ciprofloxacin concentration in plasma and in dialysate were determined by HPLC. There were no differences in plasma and dialysate kinetics in patients with and without peritonitis. Plasma levels were higher and the elimination half-life was longer than those reported for healthy subjects. Dialysate and plasma levels were significantly correlated (r2 = 0.87, P = 0.001), with dialysate levels consistently lower than plasma levels. Dialysate levels exceeded 1 mg/l in seven patients. The mean peak dialysate level (2.17±1.63 mg/l) exceeded the MIC of ciprofloxacin for 32 of 34 bacterial strains responsible for peritonitis. Ciprofloxacin shows promise as a useful oral treatment of CAPD-associated peritonitis.