Researchers have discovered a unique application for an FDA-approved drug currently used for obese patients and type 2 diabetics: treatment for cocaine dependence.
The drug, trade name Byetta, derives from a naturally occurring hormone called glucagon-like peptide-1, or GLP-1, which regulates feeding behavior. Knowing what they did about GLP-1, turned to it as a possible treatment for cocaine addicts.
The researchers formulated a straightforward hypothesis. “If GLP-1 regulates intake of palatable food, then perhaps it also regulates consumption of cocaine.”
The hypothesis turned out to be true. In a two-and-a-half year study of rats, the trio showed that when they activated GLP-1 receptors in the region of the brain that deals with reward behavior, called the ventral tegmental area, or VTA, the animals self-administered less cocaine. It’s the first time such a role has been shown for GLP-1 in the brain.
Physiologically, GLP-1 acts similarly in rat brains and human brains. Rather than injecting cocaine, the scientists modeled the way a human would take the drug by offering the study rats a lever to press for intravenous infusions. Once the animals stabilized in their drug-taking regimen, the researchers introduced the GLP-1 receptor agonist directly into the brain.
Getting to human clinical trials would go a long way toward meeting a long-term goal for the lead author on a new paper detailing these findings in the Nature journal Neuropsychopharmacology.
To move forward the GLP-1 project specifically, the team plans to next focus on the pathway it follows in the brain.