Episode Transcript
[00:00:01] Speaker A: Obesity is a very common condition that we encounter in many of our patients.
Not all patients are suitable for gastric surgery such as bariatric surgery.
Anti obesity medications are becoming more and more popular.
But are these medicines the magic potion for our patients? Are these medicines safe to take and for whom?
Professor Fikri's presentation on the impact of anti obesity drugs on gastric motility and implications for the management of dyspepsia highlighted the side effects that are common and that we all encounter in our clinics.
Dr. Asma Fikri is a neurogastroenterology consultant at University College Hospital, London and and Honorary Associate professor at University College London. Professor Fikri is the Chair of Neuro, Gastroenterology and Motility Section of the British Society of Gastroenterology.
Thank you for such a comprehensive presentation. I enjoyed your talk presenting the gastric physiology and motility and then focusing on the dysmotility effects caused by the GLP1 agonist.
As presented, this medicine slow down the gastrointestinal motility.
What type of prokinetics would you recommend to treat this patient with?
[00:01:31] Speaker B: Thank you, Maria. So, yeah, you're absolutely right. They have a lot of effects on the gut, so not only the stomach, but also the intestine and colon. But in the talk that I gave, we were talking about the stomach, weren't we? And they definitely delay gastric emptying. So patients often complain of nausea, vomiting, dyspepsia, and really you treat them like you do with anyone else who's got delayed gastric emptying. So there are a variety of prokinetics that we normally use in gastroparesis and that we can use for these patients, including metoclopramide or domperidone. Often these patients also have constipation and so things like pricalopride may be more beneficial because you can kill two birds with one stone.
As I mentioned at the talk, prakalopride does wear off, usually after a few months. So just to remember that it's an effect that lasts for a few months and then patients might get used to it and it might not be as effective, but you can use any of those.
[00:02:26] Speaker A: Thank you. Should these patients be having physiological testing to assess gastric emptying, for example?
[00:02:35] Speaker B: So that's a really good question. A lot of them, as we talked about, do have symptoms of delayed gastric emptying and so you might be tempted to do a gastric emptying study. But we know that these drugs cause delayed gastric emptying, so you'll inevitably find delayed gastric emptying on their tests.
That doesn't mean that inherently they've got gastroparesis, it means that the drug is causing delayed gastric emptying. So in some ways it's pointless to refer these patients for gastric emptying studies.
[00:03:03] Speaker A: Are there any NHS guidelines or policies for these patients for preparation prior to surgery or procedures?
[00:03:10] Speaker B: So there are no NHS based guidelines. I'm sure different hospitals have their own guidelines.
There have been some clinical practice updates that have come from the US and from Canada as well, I think, to do with how to prepare patients prior to endoscopy or surgery. And this is really to do with the anesthetic risk when they're sedated.
So for us, I guess the risks are with endoscopy, these patients, because of their delayed gastric emptying, they're more likely to have gastric retention. And so endoscopically, when we go down, we're more likely to see a stomach full of food.
So the implications for this are that they have to fast for a bit longer.
So usually the guidelines say eight hours for solids, two hours for liquids. And then there's some pragmatic guidance which I think is really good, suggests that the patients have a liquid diet for the day before the procedure.
Now, if a patient is on these medications for weight, so as a weight loss drug, then it's very easy to stop it for a week before the procedure and most patients are happy to do that. If you could, if you explain that it will impact on the procedure in terms of the risks of a general anesthetic, the risks are a little bit higher than if you're not having, than if you're not on GLP1 receptor agonist. But they're still relatively low, they're higher for longer procedures.
And if you are doing an ogd, it seems to be a bit more risky than a colon in terms of the risks of aspiration.
[00:04:41] Speaker A: So if your patient is a diabetic patient who needs to be on these medicines, would you allow them to fast longer and not stop the medicine? What would you be your recommendation?
[00:04:50] Speaker B: Yeah, absolutely. So if they're diabetic and they require the medication, then you wouldn't tell them to stop it for a week before you would get them to fast for longer. So just like you would with someone who has gastroparesis. So the guidance suggests eight hours for solids, two hours for liquids, and then go on a liquid diet the day before, because that's emptied really fast. Regardless of whether you've got delayed gastric
[00:05:11] Speaker A: emptying or not, what is the rebound effect on stopping these medicines? Are patients willing to continue despite side effects? And are there any qualitative studies?
[00:05:22] Speaker B: So from a weight loss point of view, usually they put the weight back on after they come off. So often they taper the dose down slowly to reduce that severe or excessive rebound effect. From a GI point of view, these drugs directly affect gastric function and they do it while the drug is in circulation.
Now, endogenous GLP1 has a very short half life. It lasts for for two to three minutes and then it wears off. But the drugs that we use, the GLP1 receptor agonists, have been designed to have a very long half life, so you only have to give them weekly, for example, so they remain in the circulation for a long time. But once that comes out of the circulation, so once they stop the drugs, that effect on gastric function disappears. So their motility goes back to normal and their symptoms get better.
Regardless of that, there is a group of patients who experience tachyphylaxis is which. Which means that the side effects of the medications get less as time goes on.
And in one study from the Mayo Clinic, the authors found that in a third of patients who are taking a GLP1 receptor agonist, for that study, it was liraglutide.
A third of the patients, their gastric emptying normalized after 16 weeks. So after four months on the drug. So a lot of our patients, you may recognize this will come and say when they first started taking the drugs, they felt very sick. They. But then they got used to it and those symptoms were no longer a problem.
[00:06:48] Speaker A: Would you recommend then for our patients attending our clinics to start the medicines on a very low dose and only very, very gradually increase in order to allow for these tachyphylaxis to take place?
[00:07:02] Speaker B: Exactly. So one of the recommendations, if people are very symptomatic and they don't like the GI side effects, is to maybe lower the dose and go up a lot more slowly. So titrate it up really slowly so that they can get used to the side effects. And so those side effects wear off. But as the dose increases, at each point they will get a few more side effects because the side effects are dose dependent.
[00:07:24] Speaker A: I have a few patients, and I'm sure you have too, the neurogastroenterology clinic who present on Mounjaro.
And they have side effects. They are very happy with their weight loss. But on the other hand, they say, yes, I'm vomiting every day, but my symptoms of IBS diarrhea are so much better. I don't want to stop it.
What would you do? What would you recommend to these patients?
[00:07:46] Speaker B: Well, ultimately it's patient choice, isn't it? And as doctors, our job is to educate our patients and explain the effects of the drug on their body. So for us, it's on their GI system to explain why it causes the nausea and vomiting.
And in fact, the effects on the colon do help with diarrhea. So a lot of people with IBS diarrhea and some people I know with Crohn's who have diarrhea find that on the drug, their symptoms are a lot better.
So when it's beneficial for them, that's an easy conversation because they want to have that medication. But if their symptoms are really problematic and they come and they say, I'm really happy on the drug, I'm losing weight, but I have a lot of nausea and vomiting, can you help with that? I think it's our job to explain that those side effects are the reason also that their weight is going down and that they will have to accept those side effects or reduce the dose.
[00:08:39] Speaker A: Thank you. Currently there are studies looking at the effect of the anti opacity medications, in particular the GLP1 agonists, on patients with IBS diarrhea or constipation.
Would you recommend any of these medications to any of your patients who have resistant symptoms of IBS diarrhea and they have not responded to other medications?
[00:09:02] Speaker B: That's a really good question. And patients will often ask for it because they will, they will say that they know someone who's been on it and there have been some headlines where it's helped with the diarrhea.
I think we don't have any long term data on this. There aren't really any studies looking at big data and looking at the effect on ibs D theoretically it makes sense that they might reduce diarrhea, but in some people they increase the diarrhea. So I think we need some more studies and more guidance before we routinely prescribe this for patients. If patients are on it and they find that they're better, then that's a happy side effect of the drug. But otherwise I wouldn't at the moment, with the current evidence, I wouldn't prescribe it specifically for that. And in fact, it's not licensed for that, so we can't do that.
[00:09:45] Speaker A: Anyway, thank you so much.
[00:09:47] Speaker B: Thank you very welcome.
