A drug approved for use in obese patients and type 2 diabetics may also help treat cocaine dependence, a new study has claimed.
The drug, Byetta, is derived from a naturally occurring hormone called glucagon-like peptide-1, or GLP-1, which regulates feeding behaviour.
Knowing what they did about GLP-1, researchers from University of Pennsylvania in US turned to it as a possible treatment for cocaine addicts.
In a two-and-a-half year study of rats, researchers showed that when they activated GLP-1 receptors in the region of the brain that deals with reward behaviour, called the ventral tegmental area (VTA), the animals self-administered less cocaine.
It is the first time such a role has been shown for GLP-1 in the brain, researchers said.
Physiologically, GLP-1 acts similarly in rat brains and human brains. Rather than injecting cocaine, researchers modelled the way a human would take the drug by offering the study rats a lever to press for intravenous infusions.
Once the animals stabilised in their drug-taking regimen, they introduced the GLP-1 receptor agonist directly into the brain.
“We are looking at what activation of GLP-1 receptors in the VTA does to the animal’s self-administration of cocaine. We were able to show a nice decrease in cocaine self-administration,” said Heath Schmidt from University of Pennsylvania.
“Our interest is really to understand how chronic exposure to drugs of abuse changes the brain to produce addiction-like behaviours,” Schmidt said.
The drug, approved by the US Food and Drug Administration (FDA) has already been proven safe for human use, researchers said. The findings were published in the journal Neuropsychopharmacology.