The relationship between inpatient fluoroquinolone use and Clostridium difficile-associated diarrhea.

BACKGROUND: Limited evidence suggests there may be a link between fluoroquinolone use and Clostridium difficile-associated diarrhea (CDAD), but such an association remains unclear due to conflicting data.
OBJECTIVE: To determine the relationship between inpatient fluoroquinolone use and CDAD; secondary objectives included the relationship between CDAD and fluoroquinolone selection, duration of therapy, and route of administration, as well as the association between fluoroquinolones and CDAD complications.
METHODS: We conducted a retrospective, case-control study of adult inpatients diagnosed with CDAD during the period of July 2007-July 2008. In total, 174 case patients were matched on a 1:1 basis with controls. A thorough assessment of all inpatient antibiotic use was conducted, including regimens administered at our institution within the previous 8 weeks. Odds ratios were calculated using univariate logistic-regression analysis.
RESULTS: Use of fluoroquinolones was not significantly different between patients with CDAD and matching controls (OR 1.36; 95% CI 0.09 to 2.10; p = 0.16). No relationship was found between CDAD and the individual fluoroquinolones: ciprofloxacin (OR 1.36; 95% CI 0.87 to 2.12; p = 0.18), levofloxacin (OR 1.17; 95% CI 0.62 to 2.22; p = 0.63), and moxifloxacin (OR 1.34; 95% CI 0.81 to 2.20; p = 0.25). Fluoroquinolone route of administration did not differ significantly between groups for patients receiving intravenous (OR 1.20; 95% CI 0.74 to 1.94; p = 0.46) or oral (OR 0.79; 95% CI 0.44 to 1.44; p = 0.45) therapy. Complications from CDAD were not significantly increased by fluoroquinolone use (OR 1.37; 95% CI 0.72 to 2.61; p = 0.35).
CONCLUSIONS: Inpatient administration of fluoroquinolones was not associated with CDAD at our institution. Fluoroquinolone use in patients who developed CDAD was not related to higher incidences of CDAD-related complications.