People who have an addiction to dangerous designer opioids may soon be able to mitigate their condition and avoid fatal overdoses with the help of a new vaccine, says a report published in the journal Angewandte Chemie.
A wide array of synthetic opioids is available on the black market, and their use is on the rise. Being illegal, users have no way of knowing how strong these drugs they are, and this can lead to fatal overdoses.
Fentanyl, a pain killer 50-500 times more powerful than morphine, is often mixed with or substituted for heroin by drug dealers.
Illegal laboratories have been tweaking the molecular structure of fentanyl to avoid detection by the US Drug Enforcement Administration (DEA), creating variants such as "China white" and acetyl fentanyl, recently linked to a number of deaths in Rhode Island and Pennsylvania.
According to the US Centers for Disease Control and Prevention (CDC), the number of overdose deaths involving opioids doubled from 2000-2014, partly, it is thought, due to the availability of fentanyl and its variants.
The effects of fentanyl include euphoria, drowsiness, lethargy and mellowness, but tolerance develops rapidly, so that a dose that creates a high one week will probably not provide the same high, even a few days later.
While naloxone is effective against opioid overdose, and methadone is used to treat addiction, these do not work for everyone, and many people relapse.
New vaccine triggers immune response against synthetic opioids
Scientists from The Scripps Research Institute (TSRI) in La Jolla, CA, in an attempt to "fill the gap," have carried out preclinical tests of a vaccine that prevents fentanyl from reaching the brain.
The new vaccine contains a molecule that mimics fentanyl's core structure, and it works by training the immune system to produce antibodies to neutralize the drug. If someone tries to get high from fentanyl or similar substances after having the vaccine, their antibodies will bind to the drug and prevent it from reaching the brain.
Researchers hope that by blocking the ability to feel a high, the vaccine could discourage drug-seeking and drug-taking behavior.
- In 2014, drug overdose caused the death of 47,055 Americans
- This rate was up 6.3% on 2013 and was higher than any previous year on record
- The rise coincided with reports of increased availability of fentanyl.
Antibody analyses showed that the immune system of mice continued to neutralize fentanyl for several months, after receiving three vaccinations at 2-week intervals, like a series of booster shots.
Vaccination also appeared to prevent "high" behavior among fentanyl-addicted mice, for example, they could no longer ignore discomfort. It took 30 times the normal dose of fentanyl for the drug to activate neural circuits following the treatment.
The researchers conclude that antibodies generated by the vaccine neutralized the lethal levels of fentanyl and offered protection against overdose.
This is the first time, they say, that a vaccine has been able to counter lethal doses of any drug of abuse.
The vaccine appears to protect against most fentanyl derivatives and does not seem to interact with other drug classes, such as oxycodone, so that even after vaccination, an individual would still be able to use certain painkillers for medical purposes.
Kim Janda, professor of chemistry and member of the Skaggs Institute for Chemical Biology at TSRI, says:
"We want to stay one step ahead of these clandestine laboratories making illegal opioids for black market demand. The importance of this new vaccine is that it can block the toxic effects of this drug, a first in the field."
Next, the researchers hope to design an even more potent vaccine, possibly combining anti-fentanyl and anti-heroin effects, to protect people who abuse variations that combine the two.
Medical News Today reported earlier this month that the strength of medical prescriptions contributes to opioid overdose.