Cefazolin plus netilmicin versus cefazolin plus ceftazidime for treating CAPD peritonitis: Effect on residual renal function

Background. The International Society for Peritoneal Dialysis (ISPD) treatment guidelines for continuous ambulatory peritoneal dialysis (CAPD) peritonitis 2000 recommended the use of cefazolin plus ceftazidime as the initial empirical therapy in patients with residual renal function (RRF). However, this treatment regimen has not been compared with the conventional regimen of cefazolin plus netilmicin in prospective, randomized controlled trials. Methods. Stable CAPD patients who developed clinical evidence of peritonitis were randomized to receive intraperitoneal (i.p.) cefazolin plus netilmicin or cefazolin plus ceftazidime once daily in the long dwell for 14 days. For patients with RRF (> 1 mL/minute) before entry into the study (N= 50), RRF and 24-hour urine volume were measured at days 1, 14, and 42 after commencement of i.p. antibiotic treatment. Results. One hundred and two patients were recruited into the study. The primary cure rates of i.p. cefazolin plus netilmicin and cefazolin plus ceftazidime were 66.7% and 64.7%, respectively. The overall cure rate for the 2 treatment regimens was 82.3% for both. Seven patients (14%) from each treatment group required removal of the dialysis catheters due to treatment failure. Relapse of peritonitis occurred in 2 patients (4%) in both treatment groups. Thirty-six patients with RRF at baseline achieved primary cure of their peritonitis by the assigned antibiotics. In this subgroup of patients, their RRF and daily urine volume showed significant reduction at day 14 and returned to near baseline values at day 42. The degree of reduction in RRF and urine volume did not differ significantly between the patients treated with cefazolin plus netilmicin and cefazolin plus ceftazidime. Conclusion. Intraperitoneal cefazolin plus netilmicin and cefazolin plus ceftazidime have similar efficacy as empirical treatment for CAPD peritonitis. In CAPD patients with RRF, significant but reversible reduction in RRF and 24-hour urine volume could occur after an episode of peritonitis, despite successful treatment by i.p. antibiotics. The effect of i.p. cefazolin plus netilmicin, or i.p. cefazolin plus ceftazidime on RRF in CAPD patients with peritonitis does not appear to be different. Our findings do not support the routine use of cefazolin and ceftazidime as the empirical treatment for CAPD peritonitis.