How does Suboxone treatment work, and what are its effects?
We’ve talked extensively about Suboxone (buprenorphine/naloxone), including its history and its role in medication-assisted treatment for opioid use disorder. If you’ve read some of these articles, you know that Suboxone is an opioid that eases withdrawal symptoms.
But what exactly is going on in your brain when you take Suboxone—is it different from what happens with other opioids? For those of you who want to delve a little more into the nitty gritty of why and how Suboxone works, here is some more information about its neurological effects.
First of all, what happens in your brain when you take opioids?
There are molecules in your brain called neurotransmitters that carry information between neurons (i.e. brain cells). Different types of neurotransmitters attach to different receptors on the neurons.
One type of receptors are called opioid receptors. Specifically, we’re talking about the mu (μ) opioid receptors. We have many of these opioid receptors in an area called the locus coeruleus in the brainstem. When the right kind of molecules attach to the mu opioid receptors in this area and activate them, it prevents the release of noradrenaline—a neurotransmitter that stimulates alertness and blood pressure. Preventing noradrenaline from being released causes the opposite symptoms: drowsiness, slowed respiration (breathing), and analgesic (pain relieving) effects. Activating these opioid receptions also causes the release of another neurotransmitter, called dopamine, into the nucleus accumbens, which is a brain region implicated in reward processes. This reaction causes feelings of pleasure. So the overall effect is a one-two punch of relaxation (from the suppression of noradrenaline) and pleasure (from the dopamine).
The process described above happens with neurotransmitters that naturally exist in your body called endogenous opioids (like endorphins, which make you feel good when you exercise). Chemicals that you ingest can also attach to opioid receptors. When you take full agonist opioids like heroin, fentanyl, and oxycodone, they attach to opioid receptors and activate them—causing even stronger pleasurable effects like euphoria.
If opioid receptors are natural, why is taking opioids a problem?
If you take full agonist opioids for a long time or at high potency, your brain notices the influx of opioids and “turns off” some receptors. This means that you eventually need more opioids to achieve the same effect (tolerance). In addition, when you stop taking opioids and there are not enough of them in the receptors, your brain reacts by releasing more noradrenaline than usual, causing highly unpleasant side effects like vomiting, anxiety, jitters, and pain (withdrawal). Although opioid use may feel pleasurable at first, eventually these neurological changes induce physiological dependence—opioids become a necessity to function in daily life.
In the worst-case scenario, high levels of opioid use will slow down the respiratory system enough to dangerously lower the amount of oxygen reaching the brain, causing brain damage or even death (overdose).
What does Suboxone do to help?
Suboxone is a brand name for buprenorphine and naloxone. There are other brands, like Zubsolv, as well as generic options.
Buprenorphine is an opioid that attaches to the mu opioid receptors. It has a strong binding ability, dislodging and blocking other opioids so that they become ineffective. One important difference is that it is a partial agonist instead of a full agonist, meaning that it causes limited pleasurable effect. This is usually just enough to stop withdrawal symptoms in people who have regularly used opioids, without causing euphoria. Most people report feeling “normal” rather than high when on a regimen of buprenorphine.
Buprenorphine has a ceiling effect. This means that at a certain point, taking a higher dose no longer produces a greater effect. This subverts the inclination to take more in order to get a better high. In addition, there is a lower propensity for tolerance because buprenorphine takes a longer time to dissipate than many other opioids, creating a steadier effect on the receptors.
Essentially, taking buprenorphine relieves cravings and substantially reduces the drive to turn to other, more dangerous opioids in order to maintain the status quo of an opioid-dependent brain. It thus allows the individual to function on a day-to-day basis experiencing neither withdrawals nor highs. There is also the possibility of lowering dosage over time to return the brain to its pre-dependence state (tapering).
What about other medications for opioid use disorder?
Suboxone has a few advantages over the other popular medication used to treat opioid addiction, methadone. Buprenorphine is believed to have fewer respiratory effects than methadone at high doses, reducing the risk of overdose. Because Suboxone combines naloxone with buprenorphine, it is considered to be at less risk of diversion and misuse. Naloxone is an opioid antagonist that attaches extremely strongly to the receptors and completely blocks opioids from activating them. If Suboxone is misused by being injected instead of taken orally, the naloxone kicks in, blocks the buprenorphine, and causes withdrawal. This combination helps ensure that people use Suboxone as directed. Methadone lacks that security measure. As well, methadone is a full opioid agonist and so does not have a ceiling effect. (Note that methadone is a well-supported treatment for opioid use disorder. This is not intended to disparage it, but to clarify why many clinicians prefer buprenorphine/naloxone.)
References
Buprenorphine Treatment. (2015). Retrieved from https://www.naabt.org/education/buprenorphine_treatment.cfm
Koob, G. F. (2011). Neurobiology of addiction. Focus, 9(1), 55-65.
Kosten, T. R., & George, T. P. (2002). The Neurobiology of Opioid Dependence: Implications for Treatment. Science & Practice Perspectives, 1(1), 13-20.
Barnett, P.G., Rodgers, J.H., & Bloch, D.A. (2001). A meta-analysis comparing buprenorphine to methadone for treatment of opiate dependence. Addiction, 96: 683-690.
Fiellin, D. A., Moore, B. A., Sullivan, L. E., Becker, W. C., Pantalon, M. C., Chawarski, M. C., Barry, D. T., O’Connor, P. G., & Schottenfeld, R. S. (2008) Long-Term Treatment with Buprenorphine/Naloxone in Primary Care: Results at 2–5 Years, American Journal on Addictions, 17:2, 116-120.