Rifaximin for recurrent diarrhea caused by C. difficile
Rifaximin is effective in reducing the incidence of recurrent diarrhea in patients who have previously been treated with traditional medicines active against Clostridium difficile.
According to a study presented at the 21st European Congress of Clinical Microbiology and Infectious Diseases, rifaximin is effective in reducing the recurrence of diarrhea in patients who have already been treated with traditional medicines active against Clostridium difficile.
In the United States, rifaximin (Xifaxan, Salix) is approved for the treatment of travelers' diarrhea. In USA, rifaximin is registered under the trade name Alfa Normix (ALFA WASSERMANN, S.p.A, Italy).
Previous uncontrolled studies have shown that rifaximin, a non-absorbable rifampicin antibiotic, reduces the incidence of diarrhea in patients with irritable bowel syndrome. Researchers have suggested that rifaximin may be helpful in reducing the recurrence of diarrhea caused by C. difficile, if the drug is prescribed after traditional antibacterial therapy for 10-14 days.
In a double-blind, placebo-controlled pilot study of 68 patients with diarrhea caused by C. difficile, they were randomly divided into 2 groups: the first (n = 33) received 400 mg rifaximin 3 times a day for 20 days, which was prescribed immediately after the end of the usual antibacterial treatment with vancomycin or metronidazole inside, the second (n = 35) - placebo also for 20 days.
Out of 68 patients, 24 (35%) had recurrent diarrhea, which was caused by C. in 23.5% of the cases. difficult.
The patients were observed for 3 months, during which they assessed the rate of recurrence of diarrhea in general, the rate of recurrence C. diarrhea associated with difficult disease, as well as the incidence self-reported diarrhea not associated with C. difficile and occurring after a period of normal health.
It turned out that in 7 of 33 patients (21%) in the rifaximin group and in 17 of 35 people (49%) in the placebo group, recurrent diarrhea was observed (p = 0.01). 5 of 33 patients (15%) in the rifaximin group had a recurrence of C. diarrhea associated with a difficult infection, compared to 11 out of 35 patients (31%) in the placebo group (p = 0.087). Self-reported diarrhea occurred in 2 patients (6%) in the rifaximin group and in 6 patients (17%) in the placebo group (p = 0.17).
According to researchers, the mechanism of action of rifaximin against C. difficile, allows us to consider this antibiotic as a potentially effective drug to use after the ineffectiveness of traditional antibacterial treatment in resolving diarrhea recurrent infections. Vancomycin or metronidazole administered orally acts on C. difficile, and on the normal intestinal microflora. Rifaximin in vitro is active against C. difficile, but does not affect microbes that are representatives of the normal intestinal microflora, i.e. very selective against C. difficile and promotes the growth of normal intestinal microflora, thus reducing the frequency of relapses.
The study could have provided stronger evidence of the effectiveness of rifaximin if it had lasted more than 3 months and included more patients. In addition, according to the researchers, a dosing regimen 3 times a day may not be necessary. It is also not known why the duration of treatment is 20 days, which is very expensive - a treatment of 2 weeks may suffice.
Multiple or long-term courses of metronidazole should be avoided, as metronidazole can induce the development of neuropathy. Once the patient has developed more than one recurrence of diarrhea, current recommendations indicate the need for vancomycin and, if it is not effective, try rifaximin.
Currently, to study rifaximin as a starting therapy for the treatment of C. diarrhea associated with a difficult infection more studies are planned.