The majority of people taking opioid medications use them to relieve chronic pain. Many medical cannabis patients have successfully weaned themselves off of all opioid medications in favor of only cannabis. Unfortunately, for some patients, cannabis, by itself, cannot adequately control their chronic pain. I recently wrote an article about why some people do not find cannabis to be effective in controlling their pain. Here is the link to that article. Today’s post makes the case for the usage of low doses of THC in conjunction with low doses of opioids and how each one increases the effectiveness of the other.
For those of you who have studied how the endocannabinoid system (ECS) works, you know that the cannabinoids in cannabis affect CB1 receptors in the body which act as a pain-reliever. CB1 receptors are also activated by opioid medications and provide pain relief in 2 ways; they make you feel good and they reduce pain.
A double-blind, placebo-controlled study published in Neuropsychopharmacology in February, 2018, used human subjects to test the effectiveness of 5.6% THC with 2.5mg oxycodone on controlling pain. The results showed that neither cannabis nor opioids, by themselves, controlled the pain. When used together, the participants exhibited the ability to tolerate higher levels of painful stimuli indicating that they achieved significant pain reduction.
Opioids work in the following way; they reduce the intensity of the pain signals from the injury site to your brain and they make you feel good by increasing your levels of dopamine. The problems begin when repeated opioid usage leads to an actual long-term brain change, reducing the number of opioid receptors in the brain and body. When there is a reduction of opioid receptors, you experience stronger pain signals to the brain and a reduction in the level of dopamine. That means you have to increase your tolerance which causes an increase in your dosage just to maintain the same level of pain relief. This can lead to addiction, progression to stronger drugs and an increased likelihood of overdose and death.
CB1 and Opioid Receptors
Here’s how the pain mechanism works:
- Pain begins at the injury site and travels through the spinal cord to the brain
- The pain processing areas of the brain, which include the periaqueductal gray, thalamus and cortex, are activated
The goal of any pain medication is to weaken the pain signals at the entrance and exit of the spinal cord before they get to the pain processing areas of the brain.
Researchers have identified both CB1 receptors and opioid receptors, especially the pain regulating μ-opioid receptors. They are expressed together in the spinal cord, the periaqueductal gray and the nucleus accumbens, known as the reward center. Simply put, both receptors are present in regions that can provide pain relief. They also recognized that if you activate one receptor, it elicits a response in the other as they physically interact. This means that depending on where they are found in the brain, the interaction of low doses of both drugs has a stronger effect on controlling pain than either drug by itself.
In addition to their interaction, there is an enhancement factor at play, as well. Cannabis can increase the effectiveness of opioids by increasing the body’s internal opioid levels. Reciprocally, the body’s own opioids levels can strengthen THC’s pain relieving effects.
Although there is much less research on the interaction of THC and opioids on the CB2 receptors, it is thought that they do play a role in regulating inflammation. The effects are felt most strongly at the injury site where the CB2 receptors stimulate the release of internal opioids which reduces the pain signals.
I know there are patients who would like to wean themselves off of all opioids, but are not able to do so. However, it is possible to reduce your opioid dosage drastically by combining it with cannabis usage.
Source: Leafly.com Part 3, How Cannabis Enhances the Effects of Opioids, Josh Kaplan