Immunotherapy Shows Promise in Treating Heroin Addiction
Some future treatments for heroin addiction may be based on immunotherapy (the purposeful activation of the human immune system), recent research from a Norwegian institution indicates.
For decades, pharmaceutical researchers in the U.S. and other countries have been exploring the possibility of creating anti-addiction vaccines that work by provoking a targeted response in the human immune system. In a study published in late 2014 in The Journal of Pharmacology and Experimental Therapeutics, researchers from the Norwegian Institute of Public Health explored the possibility of using immunotherapy-based vaccines to combat the effects of heroin, one of the most powerfully addictive substances known to humankind. These researchers concluded that it appears to be possible to develop an effective heroin vaccine.
Like all substances obtained directly from the opium poppy (and all synthetic substances based on naturally occurring ingredients in the opium poppy), heroin produces major changes in a part of the brain called the pleasure center. Since heroin use happens outside of any legitimate or legal context, any given individual who consumes the drug repeatedly over time can easily fall into a pattern of excessive consumption capable of making enduring pleasure center changes large enough to foster the development of physical opioid dependence and the eventual onset of heroin addiction. A heroin addict typically has serious problems that include such things as loss of the ability to limit intake of the drug, recurring urges to keep taking the drug, consumption of heroin in clearly risky situations, the need to use increasing amounts of the drug to feel any mind-altering effect and the appearance of highly unpleasant withdrawal symptoms that reinforce a rapid return to active heroin intake.
In the U.S., many heroin users start out as abusers of opioid medications normally prescribed by doctors for the treatment of serious or severe pain, coughing or diarrhea. Potential underlying reasons for the transition from prescription opioid abuse to heroin consumption include the wide availability of cheap heroin in many parts of the country and the relative difficulty associated with obtaining a consistent supply of opioid medications.
Immunotherapy and Anti-Addiction Vaccines
The human immune system plays a vital role in recognizing, attacking and eliminating dangerous microorganisms such as bacteria, viruses and fungi. Broadly speaking, the term immunotherapy applies to any effort to use vaccines or other approaches to get the immune system to respond in specific ways that help increase the odds that a person will recover from a significant illness or health problem. In the context of anti-addiction vaccines, immunotherapy researchers attempt to get the immune system to recognize molecules of a drug or medication circulating in the bloodstream, then follow up with an attack that eliminates the substance in question or stops it from triggering its typical mind-altering effects.
Vaccine for Heroin Addiction?
In the study published in The Journal of Pharmacology and Experimental Therapeutics, the Norwegian Institute of Public Health researchers used laboratory testing on rats and mice to explore the potential for developing a vaccine for heroin addiction. Scientists face particular hardships when it comes to developing a heroin vaccine, because the drug transforms into a number of other opioid substances (including the drug/medication morphine) before producing its characteristic impact on the brain. This means that the human immune system may need to recognize and attack multiple types of molecules in the bloodstream for such a vaccine to provide any real treatment benefit.
There are two basic types of vaccines: active vaccines and passive vaccines. Active vaccines make the immune system produce more “seeking and attacking cells,” while passive vaccines make the immune system’s existing cells work harder or better. The Norwegian researchers tested the effectiveness of a passive vaccine that blocks access to the brain by making molecules of heroin’s breakdown products too big to pass from the bloodstream to the brain. They specifically targeted one common heroin byproduct for their experiments.
The researchers found that they were able to stop the targeted heroin byproduct from passing into the rodents’ brains from the bloodstream. This is critically important, in part because the byproduct they targeted produces much of the extreme high that initially appears in heroin users. They believe that their work demonstrates the possibility of developing a marketable vaccine capable of helping people affected by heroin addiction. They also believe that such a vaccine could also help prevent fatal outcomes in people who overdose on heroin.