Sharp rise in use of new GLPs as metformin, sulfonylureas and insulin declines

Investigators from Mass General Brigham who examined claims data from nearly two million people between 2021 and 2023, have reported a shifting landscape for weight loss and glucose-managing medications, including a increase in the use of newly approved medications, whilst the use of medications previously common in the treatment of type 2 diabetes (including metformin, sulfonylureas and insulin) decreased.

Type 2 diabetes (Credit: Nick Youngson CC BY-SA 3.0 Pix4free)

"Taken together, these findings highlight the rapidly shifting landscape of prescribing patterns for glucose-lowering and weight-lowering medications," said lead author, Dr John W Ostrominski of the Cardiovascular Division, Division of Endocrinology, Diabetes and Hypertension, and Division of Pharmacoepidemiology and Pharmacoeconomics at Brigham and Women's Hospital, a founding member of the Mass General Brigham health care system. "These changing trends likely reflect the combination of new evidence, increased awareness and prioritisation of obesity treatment, and changing guidance for how to help patients manage these conditions."

The study examined claims data among people with commercial insurance. The researchers report that in January 2021, approximately half of the weight-lowering medications initiated by people without diabetes were GLP-1RA-based medications such as semaglutide and tirzepatide.

By December 2023, this percentage had increased to nearly 90%, with tirzepatide being the most commonly started (31%). Use of other weight-loss medications, such as phentermine and liraglutide, declined.

Among people with type 2 diabetes, 13% started GLP-1RA-based medications in January 2021. That rate rose to 35% by December 2023. Metformin, the most commonly started glucose-lowering medication in January 2021 (30%), declined to 19% by December 2023.

When the authors compared the immediate post-approval uptake of tirzepatide to other medications recently approved for type 2 diabetes or obesity, they found that the rise in tirzepatide's use was steeper and more sustained.

"We saw a sharp uptake of tirzepatide after regulatory approval—these kinds of trends are important for patients, clinicians, researchers, and policymakers to be aware of," added Ostrominski. "The rapidly expanding uptake of tirzepatide and GLP-1RA underscores the need for clinicians to become more familiar with their use, for researchers to improve understanding of their long-term effects, and for health policy that promotes sustained access and affordability."

The researchers note several limitations to the work, including that it is uncertain whether the findings from commercially insured US adults are generalizable to other populations and countries.

"Importantly, we don't yet have long-term data from outcomes trials for tirzepatide as we do for GLP-1RA, but preliminary data are reassuring," he concluded. "In the future, data comparing the benefits of tirzepatide versus semaglutide for glycaemic control, obesity management, and cardiovascular outcomes will help us have more informed conversations with patients about choosing the medication that's right for them."

The findings were reported in the paper, ‘Trends in Utilization of Glucose- and Weight-Lowering Medications After Tirzepatide Approval in the United States’, published in the Annals of Internal Medicine. To access this paper, please click here (log-in maybe required)