Researchers say their vaccine has the potential to reduce the number of deaths from opioid overdose. In the journal ACS Chemical Biology, scientists from The Scripps Research Institute (TSRI) in La Jolla, CA, describe how the vaccine stopped two opioids - oxycodone and hydrocodone - from reaching the brains of mice, reducing symptoms of a drug "high."
What is more, the vaccine appeared to reduce the toxic effects of opioids in the mice. If these results translate to humans, the researchers say the vaccine has the potential to reduce the risk of death from opioid overdose.
Opioids are medications prescribed for the treatment of chronic pain. They are among the most commonly used painkillers in the U.S., with the number of opioids sold in the country almost quadrupling since 1999. Although opioids are considered effective for pain management, their use has become a major public health concern.
The drugs are highly addictive; as well as binding to receptors in the brain that block pain perception, they also affect brain regions related to reward, which may give the user a sense of euphoria. According to the Centers for Disease Control and Prevention (CDC), almost half a million Americans died from drug overdoses between 2000-2014, and more than 6 in 10 overdose deaths involve an opioid.
Now, study co-author Kim D. Janda, the Ely R. Callaway Jr. professor of chemistry and member of the Skaggs Institute for Chemical Biology at TSRI, and team believe their vaccine has the potential to tackle the opioid epidemic.
Opioid Toxicity Slowed With Vaccine
The new vaccine - dubbed the "oxy/hydro vaccine" - is comprised of a signature opioid structure and a molecule. In essence, the vaccine utilizes the immune system's ability to identify and neutralize foreign bodies. Upon injection, it triggers an immune response by teaching the immune system to target and bind to opioid molecules and eradicate them from the bloodstream.
For their study, Janda and team tested the vaccine on mice that had been given either oxycodone or hydrocodone - two commonly prescribed opioid medications. The researchers found that the vaccine blocked the pain-inhibiting effects of the opioids, which eliminated signs of a drug high in the mice, such as ignoring pain.
"The vaccine approach stops the drug before it even gets to the brain," explains study co-author Cody J. Wenthur, a research associate in Janda's lab. "It's like a preemptive strike."
Additionally, the vaccine appeared to lower the rodents' susceptibility to fatal overdose by reducing the toxic effects of opioids; while some mice did die as a result of opioid exposure, the team notes that it took much longer for the drugs to become toxic.
"Our goal was to create a vaccine that mirrored the drug's natural structure. Clearly, this tactic provided a broadly useful opioid deterrent," says first study author Atsushi Kimishima, also a research associate in Janda's lab.
Vaccine Has 'Enormous Clinical Potential'
The team reveals that the vaccine remained effective for the duration of the 60-day study, and it is possible it that its effect can last even longer. If the vaccine proves effective in humans, the researchers say it could offer an effective alternative to current medications for addiction, which can reshape brain chemistry. Furthermore, by slowing opioids' toxicity, the vaccine may extend the amount of time available for clinical assistance in the event of overdose.
"We saw both blunting of the drug's effects and, remarkably, prevention of drug lethality. The protection against overdose death was unforeseen but clearly of enormous potential clinical benefit." - Kim D. Janda
The researchers plan to further study the vaccine's effectiveness against opioid abuse, with a particular focus on identifying the best dosage and injection schedule.
Content Originally Published By: Honor Whiteman @ Medical News Today