Efficacy and safety of XIFAXAN for IBS-D

Dr. Mark Pimentel

Executive Director, MAST Program at Cedars-Sinai Medical Center

Watch Dr. Pimentel discuss important safety information for XIFAXAN, as well as efficacy data based on clinical trials in adults with IBS-D.

In a clinical trial1:

  • 44% of patients had improvement in both abdominal pain and diarrhea (n=1074/2438)
  • 36% of responders had no symptom recurrence at 6 months (n=382/1074)
  • Primary endpoint: 38% experienced significant improvement in stool consistency and abdominal pain (n=125/328, P<0.05) vs 31% for placebo (n=97/308)
  • In clinical studies, the most common adverse reactions for XIFAXAN in IBS-D (≥2%) were nausea (3%) and ALT increased (2%)

IBS-D = irritable bowel syndrome with diarrhea

TARGET 3 Study Design1,2: XIFAXAN was evaluated in 2438 IBS-D patients. 44% (n=1074) experienced relief from an open-label course of treatment. Relief was defined as experiencing a ≥30% improvement from baseline in the weekly average abdominal pain score (based on daily self-reports) and a ≥50% reduction in the number of days in a week with a daily stool consistency of Bristol Stool Scale type 6 or 7 (mushy or watery) compared with baseline. If patients experienced a recurrence of either of their symptoms for 3 weeks of a rolling 4-week period, they entered the randomized, double-blind treatment phase. Randomized patients then received a repeat treatment with either XIFAXAN or placebo. The primary endpoint was the proportion of patients who experienced relief in both symptoms (defined exactly as in the open-label period) during the 4 weeks following repeat treatment.

References: 1. XIFAXAN [prescribing information]. Bridgewater, NJ: Salix Pharmaceuticals. 2. Lembo A, Pimentel M, Rao SS, et al. Repeat treatment with rifaximin is safe and effective in patients with diarrhea-predominant irritable bowel syndrome. Gastroenterology. 2016;151(6):1113-1121.


XIFAXAN® (rifaximin) 550 mg tablets are indicated for the reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults and for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults.

  • XIFAXAN is contraindicated in patients with a hypersensitivity to rifaximin, rifamycin antimicrobial agents, or any of the components in XIFAXAN. Hypersensitivity reactions have included exfoliative dermatitis, angioneurotic edema, and anaphylaxis.
  • Clostridium difficile-associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including XIFAXAN, and may range in severity from mild diarrhea to fatal colitis. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued.