Opioids may not be that effective at treating pain after all. As a matter of fact, a new study suggests that these medicines may aggravate pain instead of providing relief.
Opioids typically work by binding to proteins known as opioid receptors found in the brain, spinal cord, and the gastrointestinal tract. However, researchers from of the University of Colorado at Boulder (CU-Boulder) led by Prof. Peter Grace sought to find out if opioids actually work after establishing that opioid morphine aggravates pain in rats.
Even though similar studies have been conducted in the past, Grace says they only concentrated on how opioids affected pain on the short term. Now, the team wanted to find out the long-term effects of using morphine to treat chronic pain.
For the analysis, the scientists evaluated two groups of rats with chronic pain. One group was treated using morphine while the other was not.
In comparison to the group that did not receive medication, the researchers noted that chronic pain of the group morphine group got worse within five days of treatment. This effect continued over several months of treatment.
According to the scientists, the pain worsened because of a surge in glial cell signaling. Glial cells are the “immune cells” of the central nervous system and are responsible for supporting and insulating the nerve cells and helping nerve injury recovery.
The surge further activates signaling from a protein called interleukin-1beta (IL-1b), an action that leads to an over-activity of the nerve cells in the brain and spinal cord as the body responds to pain.
Commenting on the findings of their findings study co-leader Prof. Linda Watkins, CU-Boulder says “The implications for people taking opioids like morphine, oxycodone and methadone are great, since we show the short-term decision to take such opioids can have devastating consequences of making pain worse and longer lasting. This is a very ugly side to opioids that had not been recognized before.”
While opioids may worsen chronic pain, the picture is not all gloomy. The team managed to reverse the effects of morphine by using a technique known as “designer receptor exclusively activated by designer drugs” (DREADD), which entails using a targeted drug to stop the surge of glial cell receptors.
More than 100 million Americans suffer from chronic pain, and the findings of this study could serve as a wake-up call for the individuals who abuse the use of opioids. In the recent years, there has been a surge in the number of people using opioids in the United States resulting in more than 70 deaths every day.