title: Treatment of peritoneal dialysis-related peritonitis with ciprofloxacin monotherapy: clinical outcomes and bacterial susceptibility over two decades.
abstract: BACKGROUND
  There is controversy about the preferred initial antibiotic therapy for peritoneal dialysis (PD)-related peritonitis. Quinolones have been used extensively in this setting, yet their long-term effectiveness is unknown.
  
  
  OBJECTIVE
  To analyze the results of a protocol of treatment of PD-related peritonitis with ciprofloxacin, maintained over two decades.
  
  
  METHODS
  We analyzed the clinical outcome of 682 episodes of bacterial peritonitis treated with intraperitoneal ciprofloxacin monotherapy, and the time course of bacterial susceptibility to this antimicrobial, in a historical cohort of 641 PD patients (1988-2007). Main outcome variables included changes to initial therapy and rates of hospital admission, catheter removal, relapse, reinfection, PD dropout, and mortality. For comparisons we divided the study period into phases A (1988-1994), B (1995-2000), and C (2001-2007).
  
  
  RESULTS
  The incidence of Staphylococcus aureus peritonitis decreased, while the incidences of polymicrobial and negative-culture peritonitis increased after phase A. In vitro susceptibility to ciprofloxacin decreased significantly only among coagulase-negative staphylococci (87.0% susceptible strains in phase A vs 70.0% in B and 70.1% in C, p = 0.006). Overall success rates (catheter not removed and ongoing PD after the episode) remained stable, at over 85%. However, the proportion of patients treated solely with ciprofloxacin declined from 75.7% (A) to 47.3% (B) to 32.4% (C) (p < 0.0005) and admission rates increased from 12.7% to 16.8% to 24.9% respectively (p = 0.001). These changes affected all the etiologic groups except culture-negative peritonitis. In vitro resistance to ciprofloxacin was a marker of multiresistance and correlated strongly with clinical outcome of peritonitis. Among isolates susceptible to ciprofloxacin, changing initial therapy for any reason also predicted a poor outcome.
  
  
  CONCLUSIONS
  Following satisfactory early results, the effectiveness of ciprofloxacin as monotherapy for PD-related peritonitis has declined markedly in the long term. This decline cannot be explained solely by a decrease of in vitro susceptibility to this antimicrobial, which was significant only among coagulase-negative staphylococci. Resistance to ciprofloxacin is a strong marker of in vitro multiresistance and poor clinical outcome of peritonitis.
authors.affiliation: Division of Nephrology, University Hospital Juan Canalejo, A Coruña, Spain. mfontan@canalejo.org
authors.forename: Miguel Pérez
authors.initials: MP
authors.lastname: Fontán
authors.forename: Helena Díaz
authors.initials: HD
authors.lastname: Cambre
authors.forename: Ana
authors.initials: A
authors.lastname: Rodríguez-Carmona
authors.forename: Andrés López
authors.initials: AL
authors.lastname: Muñiz
authors.forename: Teresa García
authors.initials: TG
authors.lastname: Falcón
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D002648:Child; D002939:Ciprofloxacin / Q000627:therapeutic use*; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy* / Q000453:epidemiology; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy* / Q000453:epidemiology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000382:microbiology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010538:Peritonitis / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000890:Anti-Infective Agents; D002939:Ciprofloxacin