Scientists are moving closer to creating a new type of medicine to treat chronic pain – involving cannabis – that they hope will offset the deadly consequences of addictive prescription drugs.
In an animal study published in the Journal of Neuroscience, researchers at Oregon Health & Science University discovered a unique relationship between specific pain receptors in the brain and the effects of cannabis, or marijuana.
Specifically, the researchers monitored the activity of two cannabinoid receptors, called CB1 and CB2, in the brainstem, where pain is processed. The team found that the use of marijuana activates the CB2 receptor – the same receptor that is activated when a person experiences chronic pain.
The other pain receptor, CB1, experiences the opposite effect in those with chronic pain – that is, the activity in CB1 decreases. Yet the researchers found that cannabis also activates the CB1 receptor, and they believe that the interplay of the two receptors is associated with not only pain activity but the addiction that accompanies certain drugs.
Through their early investigation, the research team is hopeful they have found a new path to less lethal pain relievers. Currently, opioid overdoses account for 91 deaths every day, according to the Centers for Disease Control and Prevention (CDC).
“It may be an avenue where we can get better pain medications that are not addictive,” said lead author Dr. Susan Ingram, associate professor of Neurosurgery in the OHSU School of Medicine, in a statement.
Curbing a Devastating Epidemic
The authors are not alone in expressing a dire warning about the opioid epidemic. The CDC notes that opioid sales have quadrupled over the past 17 years despite steady rates of pain among the U.S. population. From 2000 to 2015, more than 500,000 deaths have occurred as a result of opioid overdoses.
The epidemic has resulted in skyrocketing costs to the health care system as well. Overall, the health care system incurs more than $20 billion in costs for emergency department and inpatient care due to opioid poisoning.
About 100 million Americans suffer from chronic pain, according to the American Academy of Pain Medicine. Yet despite the high incidence of pain, the researchers note that current treatment regimens can be ineffective or have harmful consequences.
“However, emerging data indicate that drugs that target the endocannabinoid system might produce analgesia with fewer side effects compared with opioids,” said Ingram.
Future treatment might take the form of “CB2 receptor-selective agonists as useful therapeutics for chronic inflammatory pain,” write the researchers.
Previous studies have shown that marijuana can help people stop abusing drugs, including opioids. The new study provides a closer look at the precise physiological processes at play, and is the first study to assess the CB1 and CB2 receptors in what the researchers call “late adolescent and adult neurons.”
The next step is to perform additional studies on these potent areas of the brain, note the researchers. They hope that further exploration can “lead to the development of a new class of pain medications.”