Hospital-wide restriction of clindamycin:: Effect on the incidence of Clostridium difficile-associated diarrhea and cost

Background: Widespread antibiotic use has been associated with increases in both bacterial resistance and nosocomial infection. Objective: To characterize the impact of hospital-wide clindamycin restriction on the incidence of Clostridium difficile-associated diarrhea and on antimicrobial prescribing practices. Design: Prospective, observational cohort study. Setting: University-affiliated Veterans Affairs Medical Center. Patients: Hospitalized patients with symptomatic diarrhea. Measurements: Clinical data on individual patients and data on antibiotic use were obtained from hospital pharmacy records. Hospital-wide use of antimicrobial agents was monitored. Isolates of C. difficile underwent antimicrobial susceptibility testing and molecular typing. Results: An outbreak of C. difficile-associated diarrhea was ca used by a clonal isolate of clindamycin-resistant C. difficile and was associated with increased use of clindamycin. Hospital-wide requirement of approval by an infectious disease consultant of clindamycin use led to an overall reduction in clindamycin use, a sustained reduction in the mean number of cases of C. difficile-associated diarrhea (11.5 cases/month compared with 3.33 cases/month; P < 0.001), and an increase in clindamycin susceptibility among C. difficile isolates (9% compared with 61%, P < 0.001). A parallel increase was noted in the use of and costs associated with other antibiotics with antianaerobic activity, including cefotetan, ticarcillin-clavulanate, and imipenem-cilastin. The hospital realized overall cost savings as a result of the decreased incidence of C. difficile-associated diarrhea. Conclusions: Hospital formulary restriction of clindamycin is an effective way to decrease the number of infections due to C. difficile. It can also lead to a return in clindamycin susceptibility among isolates and can effect cost savings to the hospital.