Weight-Loss Drug May Help Curb Opioid Addiction

A new study shows that the weight-loss drug known as lorcaserin may be effective in reducing cravings for opioid drugs. 

The study, published in ACS Chemical Neuroscience, hinged on the weight-loss drug’s effect on serotonin, a neurotransmitter that both causes the feeling of fullness and is involved in the regulation of drug reward circuitry in the brain. 

Kathryn Cunningham, a researcher at the University of Texas Medical Branch’s Center for Addiction Research, helped train rats to self-administer oxycodone when exposed to certain lights and sounds that created a drug-taking environment. While some may envision rats sitting next to lava lamps and listening to “White Rabbit,” a Texas Medical Center press release did not offer specifics.

After the rats were regularly using opioids, researchers pulled their access. Then, some of the rats were given a placebo and some given lorcaserin—and they were all dumped into the drug-taking environment. The rats on lorcaserin reacted less strongly to the drug-taking cues (i.e., they were no longer impressed by the lava lamps) and self-administered oxycodone less frequently. 

To make sure it was the lorcaserin causing the decreased interest in drugs, researchers gave some of the rats a drug that cancels lorcaserin’s effects by selectively blocking serotonin receptors—and those rats continued trying to get oxycodone.

Cunningham’s findings are novel because most opioid treatments focus on filling the opioid receptors in the brain, so that any opioids taken won’t be as effective. But sometimes, former users still relapse if they’re around certain drugs cues, like drug paraphernalia, former using buddies, or “White Rabbit” and lava lamps. The new research focused on how to anticipate responses to those triggers. 

This wasn’t Cunningham’s first time experimenting with the efficacy of the weight-loss drug in curbing addictive impulses. Previously, the Galveston-based researcher had shown that lorcaserin would limit the number of times rats would be willing to complete a given task to earn a dose of cocaine. 

“The effectiveness of lorcaserin in reducing oxycodone seeking and craving highlights the therapeutic potential for lorcaserin in the treatment of opioid use disorder,” she said in the press release. “We plan more studies to better understand how drugs like lorcaserin can help us stem the tide of addiction in America.”

The new research comes amid a rising wave of opioid abuse and drug-related fatalities. Since 1999, the numbers of deaths from prescription opioid overdose in the U.S. has quadrupled, according to CDC data.