Skip to main content

Diabetes Drug May Be Effective in Treating Addiction


Exenatide (Ex-4), a glucagonlike peptide-1 (GLP-1) receptor agonist currently used in the management of type 2 diabetes, could effectively treat drug addiction, including cocaine dependence, new research shows.
Investigators at Vanderbilt University in Nashville, Tennessee, found that mice pretreated with the drug seemed to enjoy cocaine less, spending less time in the treatment chamber following cocaine introduction, compared with mice that were not pretreated with Ex-4.
"We know that the GLP-1 receptor affects the dopaminergic system and when dopamine neurotransmission is impaired, it leads to hedonic feeding and obesity," study investigator Aurelio Galli, PhD, professor of molecular physiology and biophysics and the Vanderbilt Brain Institute, told Medscape Medical News.
"So providing animals with a GLP-1 agonist activates the GLP-1 receptor and decreases interest in highly palatable food, and we found it also works to decrease the craving for cocaine."
The study was published online October 23 in a letter to the editor in Molecular Psychiatry.
Reduced Reward
GLP-1 is released in response to food intake and acts both peripherally and centrally to regulate feeding behavior.
Emerging data suggest that peptides such as GLP-1 may also be involved in drug reward and thus could serve as a therapeutic target for the treatment of psychostimulant addiction.
GLP-1 receptors are expressed in a number of regions in the brain that are part of the reward circuit that makes drugs like cocaine addictive, said Dr. Galli.
Because drug reward and hedonic feeding behavior use overlapping brain circuitry and mechanisms, "we hypothesized that the GLP-1R [GLP-1 receptor] agonist Ex-4 would reduce the rewarding effects of cocaine," the investigators write.
Using conditioned place preference, a test in which an animal is placed into 1 of 2 separate compartments of a test chamber, mice consistently migrated to the test chamber in which they received a pleasurable injection of cocaine.
However, when researchers pretreated mice with Ex-4, the animals appeared to enjoy the drug less, spending less time in the treatment chamber containing cocaine.
The rewarding effects of cocaine were attenuated in mice pretreated with Ex-4, regardless of the pretreatment dose. In addition, the researchers found no evidence of negative side effects or addiction to Ex-4 treatment.
The authors caution that additional research is needed to verify dosing structure and to determine whether these findings extend to other psychostimulants.
However, if results from future studies are positive, there may be significant clinical implications.
"What we have demonstrated is that a brain mechanism already known to be therapeutic for the treatment of diabetes also appears to be implicated in at least certain types of drug addiction," study coauthor Gregg Stanwood, PhD, assistant professor of pharmacology and an investigator within the Vanderbilt Kennedy Center and Vanderbilt Brain Institute, said in a release.
"We found that this drug...that is already used for the medical management of diabetes reduces the rewarding effects of cocaine in animals. We suspect that this is a general mechanism that will translate to additional drugs of abuse, especially other stimulants like amphetamine and methamphetamine."
Repurposing Drugs
Nigel Greig, PhD, from the National Institute on Aging in Baltimore, Maryland, told Medscape Medical News that he and his team have been working on the GLP-1 receptor drugs in the diabetes field for many years.
More recently, a number of investigators have been repurposing these drugs for neurological disorders, mostly notably Alzheimer's and Parkinson's disease. They are currently in clinical trials to assess the drugs' potential as neuroprotective and neurotrophic agents.
"This is the first strong scientific evidence that the same drugs may be repurposed for the treatment of drug abuse, and I think the findings are very intriguing and they are worth following up," said Dr. Greig.
The authors and Dr. Greig have disclosed no relevant financial relationships.

Comments

Popular posts from this blog

Contact Precautions May Have Unintended Consequences

Contact precautions, including gloves, gowns, and isolated rooms, have helped stem the transmission of hospital pathogens but have also had some negative consequences, according to findings from a new study. Healthcare worker (HCWs) visited patients on contact precautions less frequently than other patients and spent less time with those patients when they did visit, report Daniel J. Morgan, MD, from the University of Maryland School of Medicine and the Veterans Affairs (VA) Maryland Health Care System, Baltimore, and colleagues. Moreover, patients on contact precautions also received fewer outside visitors. "Less contact with HCWs suggests that other unintended consequences of contact precautions still exist," Dr. Morgan and coauthors write. "The resulting decrease in HCW contact may lead to increased adverse events and a lower quality of patient care due to less consistent patient monitoring and poorer adherence to standard adverse event prevention methods (such...

FDA Decision Delayed for Truvada in HIV PrEP

June 11, 2012 — The US Food and Drug Administration (FDA) has delayed its decision on allowing the use of tenofovir disoproxil fumarate/emtricitabine ( Truvada , Gilead) as preexposure prophylaxis (PrEP) so that the proposed risk evaluation and mitigation strategy (REMS) can be reviewed. In early May, the FDA's Antiviral Drugs Advisory Committee  strongly backed  approval of the first-ever drug for the prevention of sexually acquired HIV-1 infection. However, concerns by the panel at the time included that people may neglect condom use if they feel they are protected by PrEP. Panelists were also concerned that uninfected people taking PrEP who become infected with HIV may not switch to a 3-drug regimen as recommended. According to the company, the FDA has postponed the target date to September 14 so it can review Gilead's REMS plan to help ensure that patients will not misuse the drug. The committee's recommendation for supplemental approval of tenofovir/emtricit...

Antidepressants Linked to Higher Diabetes Risk in Kids

Pediatric patients who use antidepressants may have an elevated risk for type 2 diabetes, the authors of a new study report. In a retrospective cohort study of more than 119,000 youths 5 to 20 years of age, the risk for incident type 2 diabetes was nearly twice as high among current users of certain types of antidepressants as among former users, Mehmet Burcu, PhD, and colleagues report in an article  published online October 16 in  JAMA Pediatrics . The risk intensified with increasing duration of use, greater cumulative doses, and higher daily doses of these antidepressants. The findings point to a growing need for closer monitoring of these products, including greater balancing of risks and benefits, in the pediatric population, the authors caution. They undertook the study because, despite growing evidence of an association between antidepressant use and an increased risk for type 2 diabetes in adults, similar research in pediatric patients was scarce. "To our know...