Differences in abstinence rates were not statistically significant.
GLP-1 receptor agonists may aid smoking cessation by curbing cravings and mitigating weight gain, which often are impediments in quitting, according to a presentation at the American Psychiatric Association Annual Meeting.
"Cigarette smoking is a leading cause of preventable death and disease in the USA," Débora Xavier, MD, teaching assistantprinciples and practice of clinical researchHarvard T.H. Chan School of Public Health, .
"Although there are some therapies, long-term abstinence is still highly challenging, both due to intense cravings as well as post-cessation weight gain," she continued. "This is particularly true in vulnerable populations such as women and obese patients."
Although GLP-1 receptor agonists have been approved for obesity and diabetes, Xavier said, their role in smoking cessation remains unclear, prompting her and her colleagues to conduct a systematic review and meta-analysis.
A review of PubMed, EMBASE and Cochrane from inception through October 2024 yielded three studies from Denmark, Switzerland and the United States comprising 410 patients, including 207 who received GLP-1 receptor agonists.
The Danish study compared 2 mg weekly doses of exenatide (Byetta, AstraZeneca) with placebo and cognitive behavioral therapy as a control for smoking status at 6 and 12 months based on self-reported data.
The Swiss study compared 1.5 mg weekly doses of dulaglutide (Trulicity, Eli Lilly) with placebo, varenicline and counseling as a control for 12-week abstinence confirmed by carbon monoxide breath testing.
The study compared 2 mg weekly doses of exenatide with placebo, nicotine patch and counseling for 6-week abstinence also confirmed by carbon monoxide breath testing.
"Patients from the group receiving GLP-1 receptor agonists experienced less weight gain, with some of them even losing weight in comparison to the control group," Xavier said.
Mean differences in post-cessation weight gain between the treatment and control groups included -2.9 kg (95% CI, -3.53 to -2.27) in the Swiss study, -1.56 kg (95% CI, -3.58 to 0.45) in the study, and -2.59 (95% CI, -3.7 to -1.48) overall.
"Patients usually gain 4 to 5 kilograms after they quit, so that's one of the most common reasons for relapsing," Xavier said. "But patients taking these medications on average lost weight."
Although heterogeneity was moderate at 35%, Xavier, she still categorized these findings as significant.
Odds ratios for abstinence in the treatment group included 1.12 (95% CI, 0.44-2.88) for the Danish study, 0.92 (95% CI, 0.55-1.54) for the Swiss study, 2.36 (95% CI, 0.93-5.93) for the study, and 1.22 (95% CI, 0.71-2.1) overall.
"We could not find statistical significance regarding abstinence rates," Xavier said. "The odds ratio was slightly above , but it was not conclusive."
Based on these findings, the researchers concluded that GLP-1 receptor agonists could be used as a safe adjunctive therapy for smoking therapy by mitigating the weight gain that typically comes with quitting, particularly for patients who are more prone to relapse or otherwise vulnerable.
"But further research is needed to explore the potential across different patient subgroups, including those with obesity," she said.
Xavier also cautioned that these findings only serve to generate a hypothesis and that physicians should not yet recommend that patients use these drugs as replacements for traditional alternative therapies to quit smoking.
"Off-label prescriptions should be individualized," she said.
Further, Xavier noted that she and her colleagues did not assess possible psychiatric side effects with these drugs in the studies they reviewed, so they could not say that these GLP-1 receptor agonists were completely safe in their own findings.
"What I can say is that there is a value to the fact that these drugs are FDA approved," she said. "Overall, they're considered safe, compared to other experimental drugs."