Posts Tagged ‘heroin vaccine’

On the Horizon: Heroin Vaccine

aaaaaaahorizon

In a May issue of the Proceedings of the National Academy of Sciences, scientists at the Scripps Research Institute in California reported their success using a heroin vaccine in rats. The lead author of the study, Joel Schlosburg, works with Dr. George Koob, renowned and accomplished scientist who heads the team at Scripps.

This vaccine is still only in the animal phase of study. Scientists have developed a vaccine that stimulates the rat body immune system to recognize heroin and its metabolic byproducts. The immune system sees these substances as pathogens which must be got rid of, and manufactures antibodies against the compounds. After the antibodies bind to the heroin and its active metabolites, it gets further metabolized into harmless compounds that are eliminated from the body without ever crossing the blood brain barrier. In other words, the vaccine binding prevents this powerfully reinforcing opioid from ever getting into the pleasure centers of the brain to cause euphoria, or a “high.”

The first studies in rats are promising. This vaccine is postulated as a way to prevent heroin overdoses, since vaccinated addicts will no longer get euphoria from the drug. However, similar studies have been done with cocaine, and some human subjects could over-ride that vaccine by taking more cocaine, and were still able to get high. Dr. Koob says that with this new heroin vaccine, it would take a very large amount of heroin to over-ride the vaccine, or to cause an overdose. The rats in this heroin vaccine study didn’t try to load themselves with more heroin, a positive sign.

The vaccine wouldn’t affect opioid medications like methadone or buprenorphine, and so the heroin vaccine could theoretically be used along with these standard opioid addiction treatments.

Researchers took pains to make clear this vaccine is not a magic bullet. Once a vaccinated addict is subjected to cues associated with past heroin use, like being back in an old neighborhood, craving will still occur and the vaccinated addict may still use heroin in response to that craving, despite a lack of euphoria once it is used.

Also, it won’t be effective on most opioids contained in prescription pain pills. This means other opioids can still be useful if a vaccine-treated patient needs pain control… but it also means a vaccine-treated patient could still get high from non-heroin opioids. My fear is that a heroin addict would just switch to misusing prescription opioids.

Even with the vaccine, addicts still must have the psychosocial aspects of treatment in order to overcome addiction. It should be used as a part of a comprehensive treatment program.

Human trials may begin as early as the end of this year.

Schlosburg et.al., “Dynamic vaccine blocks relapse to compulsive intake of heroin,” Proceedings of the National Academy of Sciences of the United States of America, 2013 110 (22) 8751-8752.