Rifaximin may prevent multiple recurrences of CDAD

Data indicate that oral rifaximin can prevent recurrences of Clostridium difficile-associated diarrhea (CDAD) in patients treated previously with vancomycin, said presenters at the American College of Gastroenterology Annual Scientific Meeting (ACG) in Las Vegas, Nev.

Metronidazole and vancomycin are the 2 therapies most commonly used to treat CDAD, and although most patients will respond to 1 of these therapies, diarrhea recurs in ≥20% of cases. Furthermore, fulminant disease has resulted in colectomies, clinical sepsis, and death.

"We're aiming to interrupt the cycle of multiple recurrences of C difficile," said Stuart Johnson, MD, associate professor of medicine, Loyola University, Chicago, Ill. "About 1 in 5 have a recurrence, and a smaller group has multiple recurrences in whom the symptoms come back within days or weeks of stopping vancomycin."

After treatment with rifaximin, "6 of the 7 patients had no further CDAD episodes when followed for 2 to 12 months," Dr Johnson said. The exception was a dialysis patient whose symptoms eventually resolved but who developed a resistant isolate. Two patients required additional antibiotics for the treatment of urinary tract infections within weeks of stopping rifaximin.

In a prospective, open-label trial also presented at the ACG meeting, rifaximin 400 mg 3 times daily was studied as first-line therapy in 13 patients (5 men and 8 women) with CDAD. Eight patients completed the protocol, receiving rifaximin for 10 days. Seven of the 8 patients responded to therapy at Day 10 and had no relapses at 2 weeks.

Longer-term follow-up for a median of 162 days demonstrated 1 confirmed case of CDAD at 52 days in a patient with a prolonged hospitalization after placement of a ventricular assist device.

Another study of 19 patients with newly diagnosed or recurrent CDAD found complete resolution of symptoms in 17 patients (89%) after treatment with rifaximin 400 mg 2 or 3 times daily for 10 to 14 days.