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Antibiotic shows lasting effects against diarrhea-focused irritable bowel syndrome


2 Star

Antibiotic shows lasting effects against diarrhea-focused irritable bowel syndrome

Our Review Summary

The 457 word story presents a glowing appraisal of a study reported in an abstract at a scientific meeting.  The study has not been subjected to peer review and the abstract provided is, by its very nature, incomplete in many of the study details necessary to draw any definitive conclusions. Despite these limitations, the headline suggests the antibiotic has been demonstrated to be effective and its effects are "lasting."  The information on the disease, the approach used, the study results and the interpretation is provided by the senior author of the study.  The study results are not accurately depicted and no statistics are provided to support the notion that the drug reduced symptoms as compared to placebo.  The story correctly notes the linkages between the study, the senior investigator and the manufacturer of the drug. 

Unfortunately, many patients with Irritable Bowel Syndrome are severely impacted by the symptoms and do not find adequate relief or long term relief from available treatments.  As a result, many resort to off label use of available drugs to combat the disorder.  The primary investigator of the study has written a book entitled, "A New IBS Solution" in which he promotes among other treatments the use of rifaximin, a use that has yet to be approved by the FDA.


Why This Matters

New treatments for this common, sometimes debilitating disorder would be most welcome. Despite suggestions of an association between IBS symptoms and bacterial overgrowth in the small intestines, the role of antibiotics has not been clearly established. While the new data are encouraging, especially for those with severe symptoms, the article is overly optimistic considering that the study was presented at a conference.


Does the story adequately discuss the costs of the intervention?

Not Satisfactory

Costs of this drug are not discussed – an interesting oversight since the drug is commercially available and the costs are known. 

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

This criterion shines a light on a significant flaw, and it’s a great example of why we ask this question. The story’s first sentence tell us that new research demonstrates that "rifamixin can provide long-last relief for patients with IBS […]." Based on that sentence, guess how many subjects in the study experienced relief? No seriously, guess.

According to the abstract, about 40% of those who received the drug experienced relief. In comparison, about 30% of those who were given a placebo experienced relief. The placebo effect has a significant role in the treatment of IBS. Without quantifying results, comparing them to the outcomes in the comparison group, and giving us the statistical significance, you can make any treatment seem like a superhero if you want to. The research itself may prove significant and beneficial to the world of medicine, but you would not have known from this article that the drug didn’t work for most people.

Note that the data we quote above refer to the key measurement of the study (its primary endpoint): the number of people who experienced relief for at least 2 weeks during the first month following the course of treatment. Results for more sustained relief, cited qualitatively in the story with the line "effects lasted at least 10 weeks," are not presented in the abstract, so we don’t know how many subjects taking the drug actually experienced sustained relief, and how that compares to the result for the placebo group. This point underscores why results from conference presentations should be wrapped in some caution. Without a full publication, we and the medical community at large don’t have a full set of data to check.

We also find fault with the vague quote that "this is the first drug you take for two weeks and stay better after that." Perhaps the lead investigator’s quote has been taken out of context. The study took place over 3 months (and, again, not even the abstract provides data after week 6). Since IBS is generally a lifelong disease with no known cure, this unbounded statement could be read by those with IBS as implying that a cure has been found.

Does the story adequately explain/quantify the harms of the intervention?

Not Satisfactory

No specific harms or rates of harms are mentioned, only that the treatment approach was designed to achieve the maximum benefit with minimal side effects. The abstract itself states that in this study the safety profile of the group receiving rifaximin was similar to that receiving placebo.

In addition, we think it’s a little strong to claim that rifaximin "is unable to pass through the walls of the intestine and thus has no effects on the rest of the body." The drug is indeed minimally absorbed, and only a limited amount reaches the rest of the body, but there is some systemic exposure.

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

The story describes a few key points about the research: the large number of subjects, the use of a placebo control, and the fact that it was conducted as part of the process of obtaining FDA approval for the drug company to market the drug for IBS. Of note, the story also points out that the results were presented at a conference, and that this evidence applies to the specific form of IBS that is not characterized by constipation. (The research abstract itself calls it "non-constipated IBS.")

However, one big omission prevents us from giving a satisfactory rating: the story fails to mention that data presented at conferences is preliminary. While the studies themselves were Phase 3, a fairly advanced phase of human research, the investigators’ report of that research hasn’t gone through the peer review that happens when you try to publish a study. It’s the difference between reading a draft bulletin and a complete, final report that has been vetted and blessed by independent experts who were not affiliated with the researchers, their research, or the drug maker. The preliminary information in the presentation and the abstract from the conference don’t allow us to fully evaluate the methods and results.

On a lesser note, while the story refers to a singular clinical trial, in fact the results discussed are pooled from two separate trials (TARGET 1 and TARGET 2).

Does the story commit disease-mongering?


No overt disease-mongering.

Does the story use independent sources and identify conflicts of interest?

Not Satisfactory

The story strikes out on this criterion for failing to consult a single independent source. As a result, although it doesn’t appear that the author copied and pasted the news release, would it read any differently if he had? The lack of independent analysis permeates the tone of the entire story.

The article does identify several conflicts of interest, including financial ties to the drug manufacturer. We give it points for that observation. But without independent eyes on the investigator’s claims, we’re unsure if they reflect the general world of medical research or current practice. There is some good historical background on his past work in the article. (And note that Dr. Pimentel and colleagues have for years championed this line of thinking, and he published a 2005 book for patients, A New IBS Solution, discussing bacterial overgrowth and the benefits of rifaximin for this type of IBS.) But the article gives us no sense of the current evidence, only his opinion. Despite his claim that his work is no longer controversial, we don’t know if how mainstream or not his ideas are, or how often overgrowth is responsible for cases of IBS. Our reading of the literature reveals that the situation is not as uncontroversial as it seems. Independent sources would have placed the claims in context.

Does the story compare the new approach with existing alternatives?

Not Satisfactory

The article states that "Most treatments are aimed at the symptoms and have little effect on the course of the disease." The comparison is vague and the message unclear, because that sentence as written tells us that some other drugs do affect the course of the disease, and more than a little.

Later comes the quote that "this is the first drug you take for two weeks and stay better after that." We’re unsure which result was unique. Is it that rifaximin is the first drug to provide lasting relief? Or is it that other drugs provide relief but only after longer courses of therapy? Regardless, the comparative significance of the new approach would have meant a lot more had it been corroborated by someone who doesn’t have financial ties to the drug-maker.

Among the missing detail, it may have beem nice to include a discussion of the limits of current treatments for IBS and the nonpharmacologic approaches.

Does the story establish the availability of the treatment/test/product/procedure?


The author explains that the drug is currently available and approved for other uses.

Does the story establish the true novelty of the approach?


We learn the history, rationale, and current regulatory status of the treatment approach.

Does the story appear to rely solely or largely on a news release?


The story does not appear to rely solely on the news release.

Total Score: 4 of 10 Satisfactory


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