GLP-1s Hold Promise for Addiction but Questions Remain

Glucagon-like peptide 1 receptor agonist (GLP-1) prescriptions for diabetes and obesity treatment are soaring, as is the interest in their potential for treating an array of other conditions. One area in particular is addiction, which, like obesity and diabetes, has been increasing, both in terms of case numbers and deaths from drug overdose, excessive alcohol use, and tobacco/e-cigarettes.

So far, data supporting GLP-1 use in addiction are limited to preclinical studies, anecdotal evidence, a few cohort analyses, and randomized clinical trials. But the chatter among researchers and clinicians, not to mention patients, portends its promise.

“The evidence is very preliminary and very exciting,” Nora D. Volkow, MD, director of the National Institute on Drug Abuse (NIDA), told Medscape Medical News. “The studies have been going on for more than a decade looking at the effects of GLP medications, mostly first generation and predominantly in rodents,” she said.

GLP “drugs like exenatide and liraglutide all reduced consumption of nicotine, of alcohol, of cocaine, and response to opioids,” Volkow said.

Clinical, Real-World Data Promising

Second-generation agents like semaglutide appear to hold greater promise than their first-generation counterparts. Volkow noted that not only is semaglutide a “much more potent drug,” but she pointed to recent findings that saw significant declines in heavy drinking days among patients with alcohol use disorder (AUD).

At the Research Society on Alcohol’s annual meeting this past June, University of North Carolina School of Medicine, Chapel Hill, North Carolina, researchers presented findings of a 2-month, phase 2, randomized clinical trial comparing two low doses (0.25 mg/wk, 0.5 mg/wk) of semaglutide to placebo in 48 participants reporting symptoms of AUD. Though preliminary and unpublished, the data showed a reduction in drinking quantity and heavy drinking in the semaglutide vs placebo groups.

Real-world evidence from electronic health records has also underscored the potential benefit of semaglutide in AUD. In a 12-month retrospective cohort analysis of the records of patients with obesity and no prior AUD diagnosis prescribed semaglutide (n = 45,797) or non-GLP-1 anti-obesity medications (naltrexone, topiramate, n = 38,028), semaglutide was associated with a 50% lower risk for a recurrent AUD diagnosis and a 56% significantly lower risk for incidence AUD diagnosis across gender, age group, and race, and in patients with/without type 2 diabetes.

Likewise, findings from another cohort analysis assigned 1306 treatment-naive patients with type 2 diabetes and no prior AUD diagnosis to semaglutide or non-GLP-1 anti-diabetes medications and followed them for 12 months. Compared with people prescribed non-GLP-1 diabetes medications, those who took semaglutide had a 42% lower risk for recurrent alcohol use diagnosis, consistent across gender, age group, and race, whether the person had been diagnosed with obesity.

However, AUD is not the only addiction where semaglutide appears to have potential benefit. Cohort studies conducted by Volkow and her colleagues have suggested as much as a 78% reduced risk for opioid overdose in patients with comorbid obesity and type 2 diabetes) and a 44% reduction in cannabis use disorder in type 2 diabetes patients without a prior cannabis use disorder history.

Unclear Mechanisms, Multiple Theories

It’s not entirely clear how semaglutide provides a path for addicts to reduce their cravings or which patients might benefit most.

Preclinical studies have suggested that GLP-1 receptors are expressed throughout the mesolimbic dopamine system and transmit dopamine directly to reward centers in the forebrain, for example, the nucleus accumbens. The drugs appear to reduce dopamine release and transmission to these reward centers, as well as to areas that are responsible for impulse control.

“What we’re seeing is counteracting mechanisms that allow you to self-regulate are also involved in addiction, but I don’t know to what extent these medications could help strengthen that,” said Volkow.

Henry Kranzler, MD, professor of psychiatry and director of the Center for Studies of Addiction at the University of Pennsylvania’s Perelman School of Medicine in Philadelphia, has a paper in press looking at genetic correlation between body mass index (BMI) and AUD. “Genetic analysis showed that many of the same genes are working in both disorders but in opposite directions,” he said.

The bottom line is that “they share genetics, but by no means are they the same; this gives us reason to believe that the GLP-1s could be beneficial in obesity but not nearly as beneficial for treating addiction,” said Kranzler.

Behind Closed Doors

Like many people with overweight or obesity who are on semaglutide, Bridget Pilloud, a writer who divides her time between Washington State and Arizona, no longer has any desire to drink.

“I used to really enjoy sitting and slowly sipping an Old Fashioned. I used to really enjoy specific whiskeys. Now, I don’t even like the flavor; the pleasure of drinking is gone,” she said.

Inexplicably, Pilloud said that she’s also given up compulsive shopping; “The hunt and acquisition of it was always really delicious to me,” she said.

Pilloud’s experience is not unique. Angela Fitch, MD, an obesity medicine specialist, co-founder and CMO of knownwell health, and former president of the Obesity Medicine Association, has had patients on semaglutide tell her that they’re not shopping as much.

But self-reports about alcohol consumption are far more common.

A 2023 analysis of social media posts reinforced that the experience is quite common, albeit self-reported.

Researchers used machine learning attribution mapping of 68,250 posts related to GLP-1 or GLP-1/glucose-dependent insulinotropic polypeptide agonists on the Reddit platform. Among the 1580 alcohol-related posts, 71% (1134/1580) of users of either drug said they had reduced cravings and decreased desire to drink. In a remote companion study of 153 people with obesity taking semaglutide (n = 56), tirzepatide (n = 50), or neither (n = 47), there appeared to be a reduced suppression of the desire to consume alcohol, with users reporting fewer drinks and binge episodes than control individuals.

Self-reports also underscored the association between either of the medications and less stimulating/sedative effects of alcohol compared with before starting the medications and to controls.

Behind closed doors, there appears to be as much chatter about the potential of these agents for AUD and other addiction disorders as there are questions about factors like treatment duration, safety of long-term, chronic use, and dosage.

“We don’t have data around people with normal weight and how much risk that is to them if they start taking these medications for addiction and reduce their BMI as low as 18,” said Fitch.

There’s also the question of when and how to wean patients off the medications, a consideration that is quite important for patients with addiction problems, said Volkow.

“What happens when you become addicted to drugs is that you start to degrade social support systems needed for well-being,” she explained. “The big difference with drugs versus foods is that you can live happily with no drugs at all, whereas you die if you don’t eat. So, there are greater challenges in the ability to change the environment (eg, help stabilize everyday life so people have alternative reinforcers) when you remove the reward,” said Volkow.

Additional considerations range from overuse and the development of treatment-resistant obesity to the need to ensure that patients on these drugs receive ongoing management and, of course, access, noted Fitch.

Still, the NIDA coffers are open. “We’re waiting for proposals,” said Volkow.

Fitch is co-founder and CMO of knownwell health. Volkow reported no relevant financial relationships. Kranzler is a member of advisory boards for Altimmune, Clearmind Medicine, Dicerna Pharmaceuticals, Enthion Pharmaceuticals, Eli Lilly and Company, and Sophrosyne Pharmaceuticals; a consultant to Sobrera Pharma and Altimmune; the recipient of research funding and medication supplies for an investigator-initiated study from Alkermes; a member of the American Society of Clinical Psychopharmacology’s Alcohol Clinical Trials Initiative, which was supported in the past 3 years by Alkermes, Dicerna Pharmaceuticals, Ethypharm, Imbrium, Indivior, Kinnov, Eli Lilly and Company, Otsuka, and Pear; and a holder of US patent 10,900,082 titled: “Genotype-guided dosing of opioid agonists,” issued on 26 January 2021. 

Liz Scherer is an independent health journalist.