The arrival of GLP-1 receptor agonists has revolutionized treatment options for people with obesity and medical practice.
Medscape Medical News recently hosted a panel of experts across specialties — including endocrinology, gastroenterology, and obesity medicine — to discuss these potentially life-changing medications and to answer questions from the audience.
Because of the flood of queries from our audience, Medscape Medical News asked our panelists to address some of the questions that didn't make the recording. Their answers are below.
Beverly Tchang, MD, endocrinologist, Weill Cornell Medicine, New York City
Audience member: Can you initiate glucagon-like peptide-1 agonists (GLP-1 RAs) as a primary drug in a patient with obesity and newly diagnosed type 2 diabetes?
BT: We often prescribe GLP-1 RAs to individuals with type 2 diabetes as a first-line medication. Guidelines from the American Diabetes Association are really emphasizing a patient-centered approach, and metformin may not be the best first-line medication anymore.
Audience member: What should clinicians know about dose titration of GLP-1 RAs in diabetic patients with renal disease, especially those in stages IV and V chronic kidney disease?
BT: GLP-1 RAs do not need to be renally dosed, but I still recommend conferring with the patient's nephrologist because the glomerular filtration rate might decrease in the setting of dehydration. Because GLP1s suppress the thirst, not just appetite, patients can go all day without drinking water and not feel thirsty.
Michael Camilleri, MD, gastroenterologist, Mayo Clinic, Rochester, Minnesota
Audience member: Should GLP-1 RAs be held for 1 week or 4 weeks prior to surgery to reduce the patient's risk for aspiration? And is tapering required?
MC: For a patient taking liraglutide, I would hold the drug for 1 week prior to surgery. For patients taking other GLP-1 RAs, including extended exenatide, I advise holding for between 2 and 3 weeks before the procedure. It's also important to make sure the patient's diabetes is well-controlled with other medications — not GLP-1 RAs — during this period.
After surgery, you can restart GLP-1 RA therapy once there is recovery of oral food intake and normal bowel function.
Audience member: Is treatment with GLP-1 RAs appropriate for a patient with a family history of colon cancer but an otherwise unremarkable medical and family history?
MC: I have not seen a contraindication to receiving GLP-1 RAs based on a family history of colorectal cancer or other malignancies. An analysis of the French national healthcare insurance system database has suggested 1-3 years use of GLP-1 RAs (exenatide, liraglutide, and dulaglutide) may be linked with increased occurrence of thyroid cancer. Data from 37 randomized controlled trials and 19 real-world studies having 16,839 patients in placebo control group, 16,550 patients in active control group, and 13,330 patients in real-world studies were analyzed in a 2023 systematic review and meta-analysis. Compared to placebo or active control treatments, occurrence of pancreatic cancer, thyroid cancer, and all neoplasms — benign, malignant, and otherwise unspecified — were similar in the semaglutide group.
Toshi Iroku-Malize, MD, MPH, MBA, FAAFP, family physician, Zucker School of Medicine, Hempstead, New York
Audience member: What do you do about elevated liver functions after starting treatment with GLP-1 RAs, and what do you do when a patient has reached their weight loss goal?
TI-M: I recommend monitoring the liver function tests, evaluating for underlying causes, such as viral hepatitis, alcohol-related damage, or problems with other medications, and consulting a gastroenterologist or liver specialist if necessary. It's also important to discuss the risk-benefit of continuing on the GP-1 RA for that particular patient.
Audience member: What effects will GLP-1 RAs have on sleep-disordered breathing/obstructive sleep apnea (OSA)? Are you aware of any ongoing trials addressing this subject?
TI-M: GLP-1 RAs may have beneficial effects on sleep-disordered breathing and OSA through weight loss, which can lead to a reduction in excess adipose tissue, and improvements in metabolic parameters. In terms of studies, a 2023 paper addressed this question, but more research is needed.
Audience member: Is it within a psychiatric provider's scope of practice to prescribe GLP-1 agents for the reduction of weight gain associated with psychiatric medications?
TI-M: Obesity medicine is an interdisciplinary process. Numerous medications prescribed for mental health can contribute to obesity, and psychiatrists can play a role in collaborating with a patient's primary care provider and/or obesity medicine specialist to determine which medications can be adjusted or replaced. It is important to remember that obesity management is not just about medications. It requires managing nutrition and activity in addition to behavioral health issues and social determinants of health. If the clinician has had the training to manage these pillars and is comfortable managing this chronic illness — similar to diabetes, hypertension, and other conditions — then this is a possibility. Otherwise, team-based care is appropriate.
Holly Lofton, MD, obesity medicine, NYU Langone Health, New York City
Audience member: Can we safely use them on patients who have had bariatric surgery and regularly develop dumping syndrome?
HL: These medications can be used after bariatric surgery in patients who meet the criteria for pharmacologic treatment. If a patient is having postoperative symptoms of dumping syndrome or excessive gastrointestinal losses from vomiting or diarrhea, dietary adjustments and other methods of managing the dumping syndrome in gastric bypass patients should be initiated before considering GLP-1 RAs because these patients do not have a functioning pylorus in their alimentary tract and these drugs are not indicated to treat dumping syndrome. The first-line approach typically involves reducing the patient's intake of simple carbohydrates but can also include medications or surgical intervention when appropriate.
Audience member: Would teaching a patient to fast intermittently while they're on GLP-1 RAs help them preserve weight loss if they choose to wean off the medication?
HL: Personally, I feel it is best to use the titration period and the time in which the patient is actively losing weight when on GLP-1 RAs. These are the best periods to help develop an individualized treatment plan, one that includes nutrition, activity, behavior modification, and resistance training. The patient's lifestyle plan will likely change based on their environment and other factors. Intermittent fasting can be a part of such a plan. There is no consensus as to exactly which eating pattern will help patients maintain weight once they lose the physiologic benefit of the weight loss medications. However, studies have been published that demonstrate an average weight regain of 66% or greater when patients go from taking the maximum dose of a GLP-1 RA to taking none at all. Thus, patients should still be followed closely for weight regain when they discontinue a GLP-1 RA.