San Diego, California: Researchers at The Scripps Research Institute have created monoclonal antibodies that are effective against several synthetic opioids, including fentanyl and carfentanil — the deadliest of all fentanyls. Their findings could both combat opioid addiction as well as reduce overdose deaths.
The study was presented at the American College of Neuropsychopharmacology Annual Meeting.
Synthetic psychoactive drugs are becoming a serious health concern in recent years, especially fentanyls, a large family of synthetic opioids. Fentanyls can be up to 10,000 times more potent than morphine. Synthetic opioids often prove fatal due to their potency and also, are highly addictive.
Kim Janda, a researcher at The Scripps Research Institute, and colleagues looked at the efficacy of vaccines containing the newly developed opioid antibodies in animals. They tested the antibodies using a common pain response challenge, in which a heated beam of light is applied to a mouse’s tail. They then measured the time taken by the mouse to withdraw its tail: quick reaction suggests the animal is feeling pain, whereas a longer response suggests that pain response has been muted.
- Mice that were given opioids such as fentanyl or carfentanil without the antibody exhibited a big reduction in tail withdrawal, suggesting they could not sense the pain.
- When they were given the opioid-blocking antibody, the tail withdrawal was normalized, suggesting that the vaccine blocked the analgesic effects of the drug.
- The antibodies were also effective against other forms of fentanyl, including carfentanil and seven other analogs, in both pain tests and lethality studies.
The researchers also tested whether the vaccine could prevent against lethal overdose. In mice administered the vaccine followed by a dose of fentanyl that was fatal in non-vaccinated animals. All the vaccinated mice were protected from overdose.
“When it comes to the very powerful opioid carfentanil the current treatment for this opioid’s induced lethality does not work very well–it has no staying power,” says Janda. “Antibodies persist longer, and thus have enormous promise for addressing both opioid addiction as well as overdose.”
A synthetic opioid vaccine might also be used as a prophylactic measure to protect people at risk of coming into contact with the drugs, such as first responders, who have occasionally overdosed by inhaling tiny quantities of fentanyl. “These antibodies could be used to protect police, EMTs, and other first responders from inadvertent acute fentanyl exposure,” says Janda. “A canine version might even one day be used to protect drug-sniffing dogs.”