Prescription weight-loss pill helps with opiate addiction

A prescription weight-loss medication can decrease the urge to use opiates such as oxycodone, according to a recent study.

The researchers from the University of Texas Medical Branch at Galveston found that the drug, lorcaserin, reduced the use and craving for the opioid oxycodone in preclinical studies.

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.

The researchers trained rats to self-administer oxycodone while exposed to specific lights and sounds that create a drug-taking environment. Once the rats were used to regularly consuming oxycodone, they went through a period where no oxycodone was available to them. The researchers then gave lorcaserin to some of the rats while others were given a placebo and placed them in the drug-associated environment. At this point, oxycodone was again made available to the rats.

The lorcaserin rats self-administered less oxycodone and reacted less strongly to cues associated with taking the drug. In order to show that this effect was attributed to the lorcaserin, a group of rats was given lorcaserin as well as a drug that blocks the serotonin 2C receptors - thus cancelling out the effect of the lorcaserin - those rats tried very hard to get oxycodone.

"The effectiveness of lorcaserin in reducing oxycodone seeking and craving highlights the therapeutic potential for lorcaserin in the treatment of opioid use disorder," said lead author Kathryn Cunningham. "We plan more studies to better understand how drugs like lorcaserin can help us stem the tide of addiction in America."

The study is published in ACS Chemical Neuroscience.