In a study published in ACS Chemical Neuroscience, the researchers led by UTMB scientist Kathryn Cunningham found that the drug, lorcaserin, reduced the use and craving for the opioid oxycodone in preclinical studies. Cunningham is director of UTMB’s Center for Addiction Research and a professor in the department of Pharmacology and Toxicology.
Most of the treatments available to reduce opiate misuse work by occupying opioid receptors in the brain. If someone were to take an opiate while on these treatments, they would not feel the signature euphoria as strongly. However, a person’s drug-taking environment is a powerful cue that can condition someone to anticipate the experience of taking of the drug; this is called cue reactivity. People who have tried the currently available medications often relapse when they are around the people, places or paraphernalia that they associate with opiate use.
Lorcaserin, prescribed for weight loss, alters the serotonin system by changing chemical signals that affect satiety, the sensation of fullness. Serotonin regulates the brain circuitry involved in drug reward and cue reactivity, particularly though activating serotonin 2C receptors. Previous work by Cunningham and her team have shown that lorcaserin decreases how many times rats will complete a simple task to earn a dose of cocaine. However, much less is known about the involvement of the serotonin 2C receptors in altering how opiates feel rewarding for the user.