Transcript
Podcast Host (0:00)
Welcome back to Run the List, a medical education podcast in internal medicine. As a quick disclaimer, this podcast is made for educational and informational purposes only and should not be understood as medical advice under any circumstances. Before we get to the show, a quick word on the sponsors for today's episode.
Sponsor Representative (0:15)
Open Evidence is the premier AI powered medical information platform for physicians and medical students. It's like ChatGPT for anyone who practices clinical medicine. Whether you have a clinical question, a question that comes up during your literature review. If you have a question that comes up when you're trying to synthesize a topic you're going to teach, you can just go to openevidence.com, enter your question and it'll synthesize the answer for you while also linking to those actual articles. It's an outstanding resource.
Allie Shebe (0:55)
Welcome back to Run the List. I am Ali Shebe, a current third year medical student at Harvard and a recent member of the RTL team. I am back with Dr. Kumar, a gastroenterologist at Brigham and Women's Hospital and one of the co founders of rtl. For our third and final episode of our series on sibo. Today we will discuss how to treat sibo.
Dr. Kumar (1:16)
Thank you so much Allie. Let's wrap up our SIBO series today and run the list.
Allie Shebe (1:22)
So now that we are all on the same page, let me quickly summarize the past two episodes. SIBO is due to a pathological increase in bacteria in the small bowel with associated diarrhea and abdominal abdominal bloating worse after meals. Diagnosis is most commonly established via lactulose breath testing which measures methane and hydrogen produced by bacteria over time. If hydrogen rises by greater than or equal to 20 ppm or methane levels reach 10 ppm or higher at any point during the test, the diagnosis of SIBO is made. So let's return to our case for one final time. Ms. R is a 45 year old female with a history of obesity status post Roux en y gastric bypass who presents to primary care clinic with two months of worsening bloating, flatulence and diarrhea. She is found to have SIBO on breath testing and now that we have established her diagnosis, how do we treat her?
Dr. Kumar (2:20)
Thank you Allie. So the first step is to identify the subtype of Sibo that Ms. R has and there's basically two different types. She can either have hydrogen predominant SIBO or methane predominant sibo. You'll recall in our last episode on diagnosis we talked about the importance of the breath test measuring for both of those gas levels, hydrogen and methane, because the treatment is dictated by the type of pattern we see between those two gas levels. So let's assume that she has hydrogen predominant sibo. In that case, the best antibiotic approach is to use an antibiotic called rifaximin or xifaxan, which is dosed at 550mg three times a day for 14 days. You may recall this antibiotic as a use for hepatic encephalopathy in patients with cirrhosis. It is the same antibiotic, but it's a different dosage and again, it's just for a two week course. Whereas patients with cirrhosis and hepatic encephalopathy will take it indefinitely for their hepatic encephalopathy. So what is rifaximin? Well, it's a non absorbable antibiotic that has gram positive, gram negative and anaerobic coverage, and it effectively decreases the bacterial population of the small bowel. As a non absorbable antibiotic, rifaximin's primary effect is within the intestinal tract. And what's nice about that is that you have less side effects from systemic absorption. So in my experience, the most common side effects that patients may have on rifaximin are GI upset and diarrhea, because again, the main area of action is within the intestinal tract. But some patients also can develop some lightheadedness, so it's nice to caution them about these potential side effects before they start. To be honest, the main issue with rifaximin is the cost of the antibiotic, as it's very expensive if it's not covered by insurance. So I always tell my patients, let me see if I can get this antibiotic covered for you, but do not fill it if it's not covered by insurance because the cost is very, very high. So when that happens, when rifaximin is not covered, there are many other alternative antibiotics that can also be used and have been studied for sibo, and they all work generally about the same efficacy. Rifaximan, again, is our preferred antibiotic, but if it's not available or not covered, you can use these alternative antibiotics, such as augmentin, which is often my primary choice due to the safety profile of this antibiotic, as well as metronidazole, ciprofloxacin or Bactrim.
