The New GI Buddy called Rifaximin

A ray of hope has emerged for a large section of people troubled by loose consistency of stools.

To put things in perspective: loose stools or diarrhea occurring recently and for a short period is quite common, often caused by an infection of the gut, or due to a recently consumed food item that did not agree with the bowel. Most usually settle on their own, but may sometime require a pro-biotic, and occasionally a course of antibiotics.

The new “buddy” emerging for most doctors in recent times, is a drug called rifaximin. What makes this antibiotic a hot favorite is that it remains confined to the gut and does not get absorbed or interfere with other organs. Hence it tends to be very safe.

Antibiotics such as quinolones (norfloxacin, ciprofloxacin ofloxacin) or co-trimoxazoles (Bactrim/ Septran) that were used earlier for treating traveler’s diarrhea or infective diarrhea, were absorbed into the body, and hence were associated with some adverse effects (allergy, nausea, induction of antibiotic resistance with frequent use). They are still useful when one the infection is suspected to have invaded the tissues as suggested by fever or blood in stools. 

Rifaximin seems to be free of major side effects as it is poorly absorbed. It remains restricted largely to the intestinal lumen (>99%) and passes out in the stools.

It also shows “selectivity”, targeting most of the disease-causing germs, while sparing the healthy ones such as Bifidobacterium, Lactobacilli or Bacteroides. Thus the disturbance of gut flora seen with many broad-spectrum antibiotics seem to be less with Rifaximin.

Within a rather short time, Rifaximin has become the most favored prescribed drug for a variety of conditions where policing and targeting of bad intestinal germs seem to be required.

Its indications are now expanding beyond traveler’s diarrhea or acute infective diarrhea.  A section of patients suffering from irritable bowel syndrome of the diarrhea variety (IBS-D), liver cirrhosis with impending or overt coma, and SIBO (small intestinal bacterial overgrowth), all of which are associated with increased or abnormal bacteria in the gut, seem to do well with Rifaximin.

The safety profile of this drug lends itself easily for long term or frequent use, unlike other antibiotics. It is not surprising therefore to find it included in prescriptions frequently, and several pharmaceutical companies adding it in their portfolios.