A glimpse into GLP-1 receptor agonists: what to know about the market of obesity and weight loss drugs

More than 70% of adults in the US are overweight or considered obese. “It’s important not to advise a patient to simply ‘eat less and exercise more,’” said presenter Irene W. Bean, DNP, APRN, PMHNP, PNAP, FAANP, FAAN, executive director and founder of the Tennessee Nurse Practitioner Association.

Obesity is a chronic disease and global health issue, Bean said, and clinicians know that, if left untreated, obesity can lead to insulin resistance, hypertension, and dyslipidemia, and cause further complications, such as type 2 diabetes, cardiovascular disease, nonalcoholic fatty liver disease, and in some cases, death.¹

It is important to know what your options are as a provider and understand which methods of treatment might be the best fit for your patients. It is important to familiarize yourself with the proper dosages of obesity and weight loss drugs, according to Bean. Some providers may be unfamiliar with prescribing, she said, and begin at too high of a dose or raise the dosage too quickly, which can cause indigestion, nausea, and vomiting.

Bean began her presentation highlighting the mechanisms of glucagon-like peptide-1 (GLP-1) receptor agonists, which she explained are preferred to amphetamine-based therapies—like phentermine—which can worsen blood pressure, heart rate, anxiety, and insomnia.

There are several options for obesity and weight loss treatment, including oral medications, but Bean directed her presentation toward GLP-1 receptor agonist injectables.

First approved on June 4, 2021 by the US Food and Drug Administration (FDA), the once-weekly semaglutide injection 2.4 mg (Wegovy) became the first and only prescription weight loss medication with a once-weekly dosage. The approval was based on results from the Semaglutide Treatment Effect in People with Obesity (STEP) clinical trial program, which progressed through 4 phase 3a trials and involved approximately 4500 participants. In the STEP 1 trial, Bean pointed out, the 83.5% of patients achieved a loss of 5% or more body weight reduction compared to placebo (3.1%). Patients also saw an average body weight reduction of 15.6% at 68 weeks, according to study results.

The once-weekly semaglutide injection had previously been approved for treatment of type 2 diabetes under the brand name Ozempic. When used with diet and exercise, it improves glycemic control in adults with Type 2 diabetes, Bean said. It has been proven to reduce the risk of major adverse cardiovascular events, such as death, nonfatal myocardial infarction, or nonfatal stroke in adults with Type 2 diabetes and established cardiovascular disease.

Next is tirzepatide (Mounjaro), a once-weekly glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptor agonist. The first and only FDA-approved dual-action GIP and GLP-1 receptor agonist for diabetes, tirzepatide is also being studied as potential treatment for non-alcohol steatohepatitis.

A 3mg injection of liraglutide (Saxenda) is another option, Bean pointed out. This GLP-1 receptor agonist influences certain brain receptors that control appetite, and cause feelings of fullness and reduced hunger, which may result in reduced calorie consumption. It is the first and only GLP-1 receptor for weight management in adolescents (ages 12 to 17), meant to be combined with exercise and a low-calorie diet. Weight loss with liraglutide can start within 2 weeks and continues for 9 months to a year, Bean said.

This dosage of liraglutide showed significant results for lowering BMI-for-age during the clinical stages, Bean said, citing a study that followed adolescents ages 12 to 17 years with obesity. Those receiving liraglutide for 1 year reduced their BMI-for-age by 0.23%, whereas the BMI-for-age in adolescents not treated with liraglutide did not change at all.

While weight loss results can be achieved with GLP-1 agonist receptors, it is important for clinicians to know potential side effects, especially when counseling patients. These include nausea, vomiting, stomach pain, headache, dizziness, fatigue, constipation or diarrhea, heartburn or gastroesophageal reflux disease, low blood sugar in people with type 2 diabetes, mood changes, and drug interactions. Less common side effects include allergic reaction, acute pancreatitis, acute cholelithiasis, suicidal thoughts or behavior, and risk of thyroid C-cell tumors.

It is important for providers to assess patients for contraindications including heart disease, sleep apnea, hypertension, hyperlipidemia, nonalcoholic fatty liver disease, nonalcohol steatohepatitis, cholelithiasis, and cancer.

Reference

1. Bean I. Battling The Bulge: Medication Used In the Management of Obesity. Plenary session. Nurse Practitioners in Women’s Health 25th Annual Premier Women’s Healthcare Conference. Houston, Texas. September 28 to October 2.