Pulse nasal mupirocin maintenance regimen in patients undergoing continuous ambulatory peritoneal dialysis

OBJECTIVE: To determine, among patients undergoing continuous ambulatory peritoneal dialysis (CAPD) who were Staphylococcus aureus nasal carriers, if periodic brief "pulses" of nasal mupirocin calcium ointment 2% after completion of a mupirocin eradication protocol would maintain these patients free of carriage. DESIGN: Noncomparative, nonblinded study with historical controls. SETTING: A county medical center. PATIENTS: Patients in a CAPD program during the period April 1996 to May 1998. METHODS: All patients in the CAPD program had monthly nasal cultures for S aureus. After informed consent, S aureus nasal carriers were administered mupirocin to the nares twice a day for 5 days followed by nasal mupirocin twice monthly. Peritonitis and exit-site infection rates were monitored independently by CAPD nursing staff. Patients were monitored monthly for adverse effects of mupirocin and compliance with the maintenance regimen. RESULTS: Twenty-four patients in the CAPD program were enrolled in the study and had a median duration of follow-up of 8.5 months. Fifteen (63%) of the 24 patients remained free of nasal carriage on follow-up cultures. Of the 9 patients with positive nasal cultures during the study, 8 had only one positive culture. There was no significant difference in the mean yearly peritonitis rate or S aureus peritonitis rate (January 1995-May 1998). However, there was a significant decrease in the mean yearly exit-site infection rates both overall (from 8.8 episodes per 100 patients dialyzed per month in 1995 to 4.0 in 1998; P=.008) and due to S aureus (from 5.6 in 1995 to 0.9 in 1998; P=.03). Adverse effects of nasal mupirocin were mild overall; 1 patient was removed from the study due to an allergic reaction to mupirocin. CONCLUSIONS: Among CAPD patients who were S aureus nasal carriers, periodic brief treatment with nasal mupirocin after an initial eradication regimen kept them free of carriage, for the most part, with few adverse effects. The pulse mupirocin regimen offers simplicity and possibly better compliance, as well as minimizing exposure to this agent, thereby possibly reducing the risk of resistance. Further studies are warranted to compare this regimen to other commonly used mupirocin maintenance regimens in dialysis patients.