Vancomycin and ciprofloxacin: systemic antibiotic administration for peritoneal dialysis-associated peritonitis

OBJECTIVES: Peritonitis due to peritoneal dialysis (PD) is best treated empirically while waiting for the results of the dialysate culture. Thus, antibiotic therapy must cover both gram-positive and gram-negative micro-organisms. First, over a period of 9 years in a multicenter study we evaluated the efficiency of a vancomycin and ciprofloxacin combination given as the first-line treatment protocol for PD peritonitis. Second, we evaluated whether a systemic route of administration of the antibiotics could be an interesting alternative to the usual cumbersome intraperitoneal drug administration. METHODS: Vancomycin 15 mg/kg body weight, intravenous, and oral ciprofloxacin 250 mg two times per day (500 mg twice per day if residual creatinine clearance was above 3 mL/minute) were prescribed at diagnosis of peritonitis. Vancomycin injections were repeated (when blood trough level was expected to be below 12 microg/mL) in cases of gram-positive organisms for a total duration of 3 weeks. Ciprofloxacin was given for a total of 3 weeks in cases of gram-negative and a total of 10 days for susceptible gram-positive infections. RESULTS: A total of 129 episodes of peritonitis occurred; 28 of them were not included in the study because of protocol violation (n = 15) or fungal (n = 7) or fecal (n = 6) peritonitis, leaving 101 peritonitis episodes for analysis. 52 (51.5%) gram-positive and 28 (27.7%) gram-negative organisms were grown; 38 gram-positive organisms were coagulase-negative staphylococci. No organism was identified in 8 peritonitis episodes, whereas 13 peritonitis episodes were caused by more than 1 organism. 35% of the coagulase-negative staphylococci were resistant to first-generation cephalosporin and methicillin, whereas all were susceptible to vancomycin. For gram-negative bacilli, the susceptibility rate was 96% and 95% for ciprofloxacin and ceftazidime respectively. The overall treatment success rate was 77.2% (78 of the 101 peritonitis episodes): 61.4% at first intention and 15.8% after optimization of the antibiotic therapy (second intention).The protocol failed in 22.8% of the peritonitis episodes. Hospitalization was required in 52% of the peritonitis episodes; average hospitalization was 11 (range 1-45) days. CONCLUSION: Systemic vancomycin and ciprofloxacin administration is a simple and efficient first-line protocol antibiotic therapy for PD peritonitis. In our opinion, vancomycin should still be used for gram-positive infections because of its high susceptibility rate compared with first-generation cephalosporins, providing a close monitoring of the local epidemiology. Oral ciprofloxacin provides satisfactory results in gram-negative infections, comparable to those obtained with intraperitoneal ceftazidime or aminoglycosides.