In Rats, Weight-Loss Drug Lorcaserin Reduces Opiate Use
The serotonin 5HT-2c agonist drug lorcaserin (Belviq) was approved by the US Food and Drug Administration in 2012 for the treatment of obesity and weight-related conditions (such as high blood pressure, type 2 diabetes, or high cholesterol) in adults. A 2017 article by researcher Harshini Neelakantan and colleagues in the journal ACS Chemical Neuroscience reports that in rats, lorcaserin may also reduce opiate use.
The rats had been self-administering the opiate oxycodone. After receiving lorcaserin, the rats were less likely to consume oxycodone and less likely to seek it out. The rats were also less responsive to cues that had previously led them to consume oxycodone, such as lights or sounds that occurred when oxycodone was available.
Serotonin 5HT-2c receptors both regulate psychostimulant reward in the brain and play a role in reactivity to cues like the lights and sounds the rats associated with oxycodone. Lorcaserin’s effect on these serotonin receptors explains how it could reduce the rats’ drug use.
Clinical trials are expected to examine whether lorcaserin can reduce opiate use in humans in addition to assisting with weight loss.
Gabapentin May Increase Opioid-Related Deaths
The anticonvulsant gabapentin is sometimes prescribed for chronic pain conditions along with opioids. A 2017 article by researcher Tara Gomes in the journal PLOS Medicine reports that compared to opioid prescriptions alone, co-prescription of gabapentin increases the risk of an opioid-related death by 49%. The risk was increased by 60% for those receiving moderate or high doses of gabapentin (those above 900 mg/day).
The increased risk when the drugs are taken together may be because both gabapentin and opioids depress the respiratory system. Opioids also slow the gastrointestinal system, meaning that more gabapentin is absorbed by the intestines than occurs when gabapentin is prescribed alone.
Gomes and colleagues looked at cases of patients who were prescribed opioids and had opioid-related deaths, and matched these with similar patients who had not died while taking prescription opioids during the same time period. The researchers found that having taken gabapentin in the previous 120 days dramatically increased the risk of death from opioid-related causes.
Gomes and colleagues suggest that caution should be used when prescribing gabapentin and opioid drugs at the same time.
