Peritoneal Dialysis International, Vol. 13, pp 50-54 0896- 8608/93 $300 + 00 Printed in Canada All rights reserved Copyright &copy; 1993 International Society for Peritoneal Dialysis POOR RESPONSE TO ORAL CIPROFLOXACIN IN THE TREATMENT OF PERITONITIS IN PA TIENTS ON INTERMITTENT PERITONEAL DIAL YSIS Nancy M. Waite, Michael D. Johnson, Nancy R. Webster, and Ignatius W. Fong St. Michael's Hospital and University of Toronto, Toronto, Ontario, Canada .Objectives: To assess the clinical value of oral ciprofloxacin in the treatment of peritonitis in an intermittent peritoneal dialysis (IPD) population. .Design: Open nonrandomized prospective study. .Setting: Nephrology Peritoneal Dialysis Unit in a tertiary care, teaching hospital of the University of Toronto. .Patients: Subjects were participants of the IPD pro gram with an acute episode of peritonitis defined as at least two of the following: 1. signs and symptoms of peritonitis, 2. cloudy peritoneal fluid with a white blood cell count of >100!IJl, 3. demonstration of bacteria in peritoneal effluent by gram stain or culture. Ten patients were enrolled in the study, but two were withdrawn because of side effects and growth of a resistant bacteria. .Interventions: Ciprofloxacin 750 mg po q12h for 2 doses, then 750 mg daily or 500 mg twice daily for 10 days. .Main Outcome Measures: Efficacy was determined by clinical and microbiological assessment. Cure was defined as resolution of signs and symptoms with eradication of the causative organism. Peritoneal effluent and blood samples were analyzed for ciprofloxacin concentration. .Results: Ciprofloxacin was effective in treating only one of ten episodes of peritonitis. Seven patients were defined as microbiological failures (persistence or relapse of organisms). The signs and symptoms of peritonitis improved in 2 patients, but the remaining 5 failed clinically. Only Gram-positive organisms were cultured. .Conclusions: Ciprofloxacin cannot be recommended for the treatment of intermittent peritoneal dialysisrelated Gram-positive bacterial peritonitis. KEY WORDS: Ciprofloxacin; peritonitis; peritoneal dialysis; fluoroquinolones. p eritonitis continues to be an important complica tion of intermittent (IPD) and continuous ambu latory peritoneal dialysis (CAPD) (1). Tradit ional treatment of peritonitis with intraperitoneal aminoglycosides, vancomycin, or cephalosporins Correspondence to: I.W. Fong, St. Michael's Hospital, 30 Bond St., Toronto, Ontario, Canada M5B 1 W8. Received 27 February 1992; accepted 2 July 1992. often requires hospitalization, incurs an increased patient risk of drug-related toxicity, and has significant treatment- associated costs. In addition, persistent infectious episodes often limit the provision of adequate dialysis and can ultimately result in the transfer of the patient to hemodialysis. The fluoroquinolones have shown promise in the treatment of this difficult problem. They have the advantages of oral administration permitting earlier hospital discharge, a small incidence of side effects, and a broad spectrum of antimicrobial activity against Gram-negative bacilli, staphylococci (including methicillin-resistant strains), and to some extent streptococci. Therapeutic concentrations are attain able, and effective treatment of CAPD-associated perit onitis has been demonstrated with ciprofloxacin and ofloxacin (2-6). However, concern has been expressed regarding the increasing incidence of staphylococci resistance to ciprofloxacin (7,8) and the decreased activity of ciprofloxacin in different bio logi cal mediums such as the peritoneal dialysis fluid (9,10). Further, no studies have examined the effectiveness of the fluoroquinolones in an IPD population. Results from these studies encouraged us to initi ate an open trial of ciprofloxacin in the treatment of peritonitis in an IPD population and to further examine the in vitra activity of ciprofloxacin in the peritoneal fluid in this group of patients. METHODS Subjects were participants in the IPD program and were experiencing an acute episode of peritonitis defined as at least two of the following: 1. signs and symptoms ofperitonitis; 2. cloudy peritoneal effluent with a white blood cell count of >100/&mu;L, 3. demon stration of bacteria in peritoneal effluent by Gram stain and culture. Patients were excluded if they had persistent nausea and vomiting, evidence of sepsis (i.e., systolic blood pressure of <90 mm Hg or fever >39°C), previous participation in the study, or a quinolone allergy . Upon entry, the peritoneal effluent was sent for culture and sens itivity, white cell count, and anaerobic culture. Two blood cultures were taken. The peritoneal