Background: infections (CDI) is a recent epidemic in the United States particularly in the hospital setting. to metronidazole LY317615 (i.e. stools positive for toxins A and B after oral metronidazole 500?mg three times daily [t.i.d.] for 5 days). After discontinuation of metronidazole rifaximin 400?mg?t.i.d. for 14 days was prescribed. Patients were followed for 56 days and stool was tested for using polymerase chain reaction (PCR) to assess the effect of treatment. A negative PCR test result was interpreted as a favorable response to rifaximin. Results: Sixteen of 22 patients (73%) were eligible for study inclusion and completed rifaximin therapy experienced eradication of contamination (stool unfavorable for infection that is resistant to metronidazole. Larger randomized trials are needed to confirm these positive findings. contamination metronidazole resistant rifaximin Introduction infection (CDI) is the most common cause of hospital-acquired diarrhea and is responsible for approximately 15-30% of all cases of antibiotic-associated diarrhea [Muto 2005]. The incidence [McFarland 2007; Muto 2005; Pépin 2004] and severity [McFarland 2007; Muto 2005; Pépin 2004] of nosocomial CDI has been increasing in recent years despite rigorous contamination control guidelines in hospitals [McFarland 2007]. Increased frequency of CDI has been reported in US veterans administration facilities with approximately 5.1 LY317615 CDIs occurring per 1000 discharges in 1994 compared with 13.5 cases per 1000 discharges in 2004 [McFarland 2007]. The incidence of infection is increasing in Canada with 35 also.6 situations reported per 100 0 people in 1991 weighed against 156.3 cases per 100 0 in 2003 [Pépin 2004]. Furthermore to incidence the severe nature of CDI is certainly escalating. CDI with serious outcomes elevated from 5.6% in 1999 to 8.8% in 2000-2001 at a US tertiary-care teaching medical center [Muto 2005]. The reason for the elevated incidence and severity of CDI remains unknown; however possible sources include suboptimal contamination control practices emergence of a hypervirulent strain of (such as the BI/NAP1/027 strain) and poor response to standard treatment [McFarland 2007]. Standard therapy for initial and recurrent CDI is usually metronidazole 1500?mg/day for LY317615 10-14 days [Mylonakis 2001]. Regrettably the frequency of metronidazole treatment failure has increased in recent years. In a study of 908 patients diagnosed with CDI between 1982 and 1991 only 2% of patients were unresponsive to metronidazole [Olson 1994]. This is in contrast to a report demonstrating resistance to metronidazole in 22% of 207 patients with CDI diagnosed between 2003 and 2004 [Musher 2005]. Although the cause of increased metronidazole treatment failure remains unknown possibilities include increased severity of disease poor immune response of patients or resistance to antibiotics [Musher 2005]. Currently Rabbit Polyclonal to SRF (phospho-Ser77). antibiotics that elicit marginal bacterial antibiotic resistance such as rifaximin are being examined for use in patients with recurrent CDI. Rifaximin is usually a nonsystemic gut-selective antibiotic that displays minimal clinically relevant antibiotic resistance when used as directed [Scarpignato and Pelosini 2006 It has a placebo-like tolerability profile [Scarpignato and Pelosini 2006 and high activity against [Hecht 2007; Marchese 2000]. Encouraging clinical results with rifaximin for LY317615 CDI have been reported in a small randomized study in which LY317615 9 of 10 patients who received rifaximin experienced resolution of diarrheal symptoms [Boero 1990] as well as in three small nonrandomized studies [Garey 2008; Johnson toxin B gene using qualitative real-time PCR techniques (Mission Diagnostics Teterboro NJ). A favorable response to rifaximin was defined as possession of a stool sample unfavorable for toxin B gene(Physique 1). This response was managed in all patients at the final follow-up visit 56 days after treatment cessation (Physique 1). Physique 1. Percentage of patients with stool samples unfavorable for immediately after rifaximin 1200?mg/day for 14 days and at a follow up 56 times post-treatment. ITT intent-to-treat; PP per process. Table 1. Patient characteristics and demographics. In general dental rifaximin was well tolerated with few reported adverse occasions (Desk 2). Nevertheless 3 of 25 sufferers (12%) who initiated rifaximin therapy discontinued the medicine due to stomach distention. Furthermore headache.