SAN FRANCISCO — An estimated two out of five adult women in the United States have obesity, and given the potential challenges of losing pregnancy weight postpartum or staving off the weight gain associated with menopause, women are likely to be receptive toward weight management help from their Ob/Gyns. A whole new armamentarium of anti-obesity medications has become available in the past decade, providing physicians and patients with more treatment options.
Ob/Gyns are therefore well-poised to offer counseling and treatment for obesity management for their patients, Johanna G. Finkle, MD, clinical assistant professor of obstetrics and gynecology and a weight management specialist at the University of Kansas Health System, told attendees at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists (ACOG) 2024 Annual Meeting. Dr Finkle provided an extensive overview of what Ob/Gyns need to know if they are interested in prescribing anti-obesity medications or simply providing their patients with information about the available drugs.
Kitila S. Heyward, MD, an Ob/Gyn at Atrium Health Women's Care Union OB/GYN in Monroe, North Carolina, who attended the talk, tries to prescribe anti-obesity medications but has run into roadblocks that Dr Finkle's talk helped her understand how to overcome.
"I thought it was very helpful because [I] and one of my midwives, in practice, have been trying to get things prescribed, and we can't figure out the loopholes," Dr Heyward said. "Also, the failure rates are really helpful to us so that we know how to counsel people."
Even for clinicians who aren't prescribing these medications, Dr Heyward said the talk was illuminating. "It offered a better understanding of the medications that your patients are on and how it can affect things like birth control, management of surgery, pregnancy, and things along those lines from a clinical day-by-day standpoint," she said.
Starting With the Basics
Dr Finkle began by emphasizing the importance of using patient-first language in discussing obesity, which means using terms such as "weight, excess weight, overweight, body mass index," and "affected by obesity" instead of "obese, morbidly obese, heaviness, or large." She also cited the Obesity Medicine Association's definition of obesity: "A chronic, relapsing and treatable multifactorial, neurobehavioral disease, wherein an increase in body fat promotes adipose tissue dysfunction and abnormal fat mass physical forces, resulting in adverse metabolic, biomechanical, and psychosocial health consequences."
Though Dr Finkle acknowledged the limitations of relying on BMI for defining obesity, it remains the standard tool in current practice, with a BMI of 25-29.9 defining overweight and a BMI of 30 or greater defining obesity. Other diagnostic criteria for obesity in women, however, include a percentage body fat over 32% or a waist circumference of more than 35 inches.
"Women are at risk for weight gain through their entire lifespan" Dr Finkle said, and in women with polycystic ovarian syndrome, 60%-80% have pre-obesity or obesity. In menopause, the triple threat of decreased estrogen, decreased activity, and changes in diet all contribute to obesity risk and no evidence suggests that hormone therapy can prevent weight gain.
Healthy nutrition, physical activity, and behavioral modification remain key pillars of weight management, but interventions such as surgery or medications are also important tools, she said.
"One size does not fit all in terms of treatment," Dr Finkle said. "When I talk to a patient, I think about other medical complications that I can treat with these medications."
Women for whom anti-obesity medications may be indicated are those with a BMI of 30 or greater, and those with a BMI of at least 27 along with at least one obesity-related comorbidity, such as hypertension, high cholesterol, diabetes, or sleep apnea. The goal of treating obesity with medication is at least a 5%-10% reduction of body weight.
Three Pharmacotherapy Categories
Dr Finkle reviewed three basic categories of anti-obesity medications: Food and Drug Administration–approved short-term and long-term medications and then off-label drugs that can also aid in healthy weight loss. Short-term options include phentermine, diethylpropion, phendimetrazine, and benzphetamine. Long-term options include orlistat, phentermine/topiramate ER, naltrexone HCl/bupropion HCl ER, and the three GLP-1 receptor agonist drugs, liraglutide, semaglutide, and tirzepatide.
The short-term medications are stimulants that increase satiety, but adverse effects can include tachycardia, hypertension, insomnia, dry mouth, constipation, and diarrhea.
These medications are contraindicated for anyone with uncontrolled hypertension, hyperthyroidism, cardiovascular disease, MAOI use, glaucoma, or history of substance use. The goal is a 5% weight loss in 3 months, and 3 months is the maximum prescribing term.
Then Dr Finkle reviewed the side effects and contraindications for the oral long-term medications. Orlistat, which can aid in up to 5% weight loss, can result in oily stools and fecal incontinence and is contraindicated for people with chronic malabsorption or cholestasis.
Phentermine/topiramate ER, which can aid in up to 10% weight loss, can result in hypertension, paresthesia, or constipation, and is contraindicated for those with glaucoma, hyperthyroidism, and kidney stones. After the starting dose of 3.75 mg/23 mg, Dr Finkle increases patients' dose every 2 weeks, "but if they're not tolerating it, if they're having significant side effects, or they're losing weight, you do not increase the medication."
Side effects of naltrexone HCl/bupropion HCl ER, which can lead to 5%-6% weight loss, can include hypertension, suicidal ideation, and glaucoma, and it's contraindicated in those taking opioids or with a history of seizures or anorexia.
The GLP-1 Receptor Agonists
Next Dr Finkle discussed the newest but most effective medications, the GLP-1 agonists liraglutide, semaglutide, and tirzepatide. The main contraindications for these drugs are a personal or family history of medullary thyroid cancer, multiple endocrine neoplasia type II syndrome, or any hypersensitivity to this drug class. The two main serious risks are pancreatitis — a 1% risk — and gallstones. Though Dr Finkle included suicidal ideation as a potential risk of these drugs, the most recent evidence suggests there is no link between suicidal ideation and GLP-1 agonists. The most common side effects are nausea, vomiting, diarrhea, constipation, dyspepsia, and an increased heart rate, though these eventually resolve.
"We always start low with these medications," Dr Finkle said, and then titrate the dose up each week, "but if they are having awful side effects, just stay on that dose longer."
The mechanisms of all three drugs for treating obesity are similar; they work to curb central satiety and slow gastric emptying, though they also have additional mechanisms with benefits for blood glucose levels and for the liver and heart.
- Liraglutide, the first of these drugs approved, is a daily subcutaneous injection that starts at a dose of 0.6 mg and goes up to 3 mg. Patients should lose 4% of weight in 16 weeks or else they are non-responders, Dr Finkle said.
- Semaglutide, a GLP-1 agonist given as a weekly subcutaneous injection, starts at a dose of 0.25 mg and goes up to 2.4 mg; patients should expect a 5% weight loss in 16 weeks if they are responders. Long term, however, patients lose up to an average of 15% of body weight with semaglutide; a third of patients lost more than 20% of body weight in clinical trials, compared with 7%-8% of body weight loss with liraglutide. An additional benefit of semaglutide is a 20% reduction in risk of cardiovascular disease.
- Tirzepatide is a combined GLP-1 and GIP agonist, also delivered as a weekly subcutaneous injection, that should result in an estimated 5% weight loss in 16 weeks for responders. But tirzepatide is the most effective of the three, with 91% of patients losing at least 5% body weight and more than half of patients (56%) losing at least 20%.
The big drawbacks to the GLP-1 agonists, however, are their high cost, common lack of insurance coverage, and continued shortages. Dr Finkle recommended using manufacturer coupons, comparison shopping on Good Rx, and appealing prior authorization requirements to help patients pay for the GLP-1 agonists.
"Drug availability is my second problem. There's not enough drug," she said, and her patients often have to call around to different pharmacies to find out which ones are carrying the drug and at what doses. She will sometimes switch their doses as needed based on availability.
It's also important for physicians to be aware of guidance from the American Society of Anesthesiologists regarding GLP-1 agonist use prior to surgery because of their slowed gastric-emptying mechanism. To reduce the risk of aspiration, patients undergoing general anesthesia should not take liraglutide on the day of surgery, and semaglutide and tirzepatide should be held for 1 week prior to the procedure. New research in JAMA Surgery, however, suggests holding these medications for longer than a week may be wiser.
Getting Patients Started
All the short-term and long-term medications are contraindicated during pregnancy and breastfeeding, Dr Finkle said. Animal studies with GLP-1 agonists suggest adverse fetal effects when used during pregnancy, but the limited data in human studies so far have not shown a risk of major malformations. Dr Finkle said the recommendations for now are to stop all GLP-1 receptor agonist drugs 2 months before patients attempt to become pregnant and not to begin them again until after they are no longer breastfeeding.
Finally, Dr Finkle reviewed off-label medications that can result in modest weight loss, including topiramate, phentermine (not to be used for longer than 12 weeks), bupropion, naltrexone, and metformin. Metformin is likely to result in only 2% weight loss, but it may enhance the effects of GLP-1s, she said.
For Ob/Gyn who want to get their patients started on one of these medications, Dr Finkle first recommends asking patients if it's okay to discuss their weight. "Studies show that if you just ask permission to discuss someone's weight, they go on to lose weight and lose more than someone who has never been asked," Finkle said. Then she takes a history.
"When I see a patient, I ask, 'Tell me why you're here today'," Dr Finkle said.
"This gives me a lot of insight as to why they're coming in and it helps me understand where they're at in terms of other things, such as depression or anxiety with weight, and it helps me to tailor my treatment."
A full medical history is important for learning about potential contraindications or picking medications that might help with other conditions, such as topiramate for migraines. Finally, Dr Finkle advises a lab screening with a comprehensive metabolic panel, lipid panel, HbA1c, and vitamin D.
"The [comprehensive metabolic panel] allows me to know about creatinine and liver function," she said. If these are elevated, she will still prescribe GLP-1s but will monitor the values more closely. "Then I discuss options with the patient. They may be eligible for bariatric surgery or medications. We talk about lifestyle behavioral management, and then I go through the medications and we set goals."
Goals include nutrition and exercise; start modest and have them work their way up by doing activities they enjoy. In addition, patients taking GLP-1s need to eat enough protein — 80-100 grams a day, though she starts them at 60 grams — and do regular muscle strengthening since they can lose muscle mass.
Indications for referral to an obesity medicine specialist are a history of gastric bypass/sleeve surgery, having type 2 diabetes, having an eating disorder, or having failed one of these anti-obesity medications.
Finally, Dr Finkle reviewed medications that can cause weight gain: medroxyprogesterone acetate for birth control; beta-blockers for hypertension or migraine; the antidepressants amitriptyline, paroxetine, venlafaxine, and trazodone; the mood stabilizers gabapentin, lithium, valproate, and carbamazepine; and diphenhydramine and zolpidem for sleep.
No external funding was used for the talk. Dr Finkle and Dr Heyward had no disclosures.
This article originally appeared on MDedge.com, part of the Medscape Professional Network.