The viral social media phenomenon that has been cited by authorities in a warning about the potential dangers of a common antibiotic is just not true, according to hundreds of scientists and a former government health official who worked on the topic.
“Despite what it’s being told to be saying, there’s no evidence that any of the problems we know are associated with rifaximin have been caused by the use of rifaximin,” said Dr. Ann Aronson, a board member of the Institute of Medicine and director of the National AIDS Education Program.
The language in the warning for rifaximin, a gastrointestinal drug made by a company called Endo Health Solutions, was released a few days before health officials conducted a webinar on rifaximin. A transcript of the session, released by the Centers for Disease Control and Prevention, focused on the drugs’ possible impact on gout.
The CDC cited the widely circulated story in 2013, and told users of rifaximin to consult a pharmacist if they experienced anything unusual. “CVS,” the CDC said in an announcement, “is advising patients that, after a recent product study, they should stop taking omadacycline if they experience stomach cramps, blood in their stools, or itching around the spots of itchy gouty redness.”
The CDC’s warning “serves as a warning, not just for people who take the drug, but for people who may be taking this drug and should talk to their health care provider about the drug,” the CDC said in the statement released Friday.
The statement highlighted a paper published last year in the New England Journal of Medicine, which looked at a different class of drugs, opioids, and said that when a patient takes a particular opioid, “the risk of developing a disorder associated with opioid use increases twofold, relative to someone who takes a placebo.” The CDC used a similar conclusion for rifaximin, but “the reason for this result is not clear.”
Whatever happened to patients who started taking the drug with no problems?
“It’s possible,” Dr. Sara Bleich, a professor of epidemiology at Johns Hopkins Bloomberg School of Public Health said in an interview.
On Friday, Dr. Barbara Perry, chair of pharmacology and toxicology at the University of Michigan, said: “There’s no direct link between omadacycline and gout.”
Rifaximin treats bloating and cramping, sores on the skin, and with diarrhoea. It is used to treat gastrointestinal disorders, including Crohn’s disease, and it is used to ease pain of opioid drug withdrawal.
Rifaximin was developed by Endo and is made in a process that involves the production of a similar antibiotic drug called U.S. 1005.
Part of the excitement over the drug began when a study in 2012 showed that 28 percent of people taking the drug experienced a new liver injury after about four months, according to FDA records. The study was stopped before there was any evidence of serious injury.
A 2013 study published in the Journal of the American Medical Association called that conclusion into question, and concluded that the early findings — that rifaximin caused infections — might have resulted from errors in the manufacturing process.
In a separate study, published last year in the New England Journal of Medicine, rifaximin was found to be effective in the treatment of Crohn’s disease, but researchers were unable to conclusively show it reduced the length of an infection or resulted in less illness.