Side Effects of Antibiotics May Increase The Risk of Opioid Abuse, According to New Study

Combined use of antibiotics and powerful painkilling medications may increase an individuals risk of opioid abuse, according to the findings of a new study.

Researchers with the University of California San Diego indicate that side effects of antibiotics taken with opioids could lead to a change in the body’s microbiome, which affects how the brain responds to opioids and increase the risk of addiction.

The findings were published this week in the journal eNeuro, involving a study with rats, where researchers tested the theory that antibiotics affect addiction. They gave some rats antibiotics for two weeks, depleting their gut micro biome by about 80%. Then all rats in the study were given oxycodone, a strong opioid painkiller.

Doctors often prescribe both opioids and antibiotics to treat pain and ward off infection after surgery. However, antibiotics also kill the good bacteria in the gut microbiome.

Rats that received both drugs displayed significant changes in how their brains responded to opioids. They showed altered sensitivity in brain areas implicated in addiction, and exhibited changes to neuronal ensemble activation.

All of the rats in the study were given opioids and became dependent on the painkillers. However, some rats went into withdrawal when they didn’t get the painkillers and some did not. According to the findings, rats who were not given antibiotics experienced withdrawal, while the rats that received antibiotics did not.

The researchers determined that the rats whose microbiomes were depleted by antibiotic use experienced higher levels of opioid intoxication. However, taking antibiotics along with opioids also appeared to weaken the effects of drug withdrawal when they were not given the opioids. While that may seem like a positive development at first, the researchers warned that fewer withdrawal symptoms can lead to a higher risk of drug abuse.

Gut bacteria may change the way the brain responds to narcotics, the researchers determined. Rats given antibiotics and opioids had more activated neurons in the regions of the brain that regulate stress and pain. The study’s findings suggest bacteria in the gut may influence brain health and play a role in brain disorders, including addiction.

The study does not prove cause and effect, but shows a link between antibiotic use and opioid addiction, according to the researchers. However, the side effects of the alterations on the microbiome and gut-brain axis during intoxication and withdrawal still need to be studied further to determine the exact connections, they concluded.

Opioid abuse and addiction affect more than 2 million Americans. Opioids now account for 70% of all overdose deaths. Doctor overprescribing is largely implicated in the worsening of the epidemic, as many doctors prescribe painkillers without a documented pain diagnosis.