Why Is Suboxone Taken Sublingually?
While we are used to swallowing most of the medications we take, Suboxone (buprenorphine/naloxone) is different in that it is most often taken under the tongue (sublingually) or on the cheek (buccally).
What is Suboxone?
Suboxone is a brand of buprenorphine/naloxone. There are other brands, such as Zubsolv, as well as a generic version. Suboxone is a combination of two drugs that work on the body’s opioid receptors.
Buprenorphine is a semi-synthetic opioid derived from a compound found in the opium poppy. Unlike other opioids like heroin, methadone and oxycodone, buprenorphine is a partial opioid agonist. An agonist is a molecule that activates something in the body, in this case the opioid receptors. At low doses, buprenorphine has the same effects, such as pain relief and euphoria, as other opioids but at higher doses the effect levels off because buprenorphine does not bind to the receptors as completely as other opioids. This is known as the “plateau effect” and is why there is less of a risk of adverse effects, such as difficulty breathing, with buprenorphine. Buprenorphine is also different from other opioids because it interacts with more than one type of opioid receptor, whereas other opioids only interact with the mu opioid receptor. In addition to treating opioid use disorder, buprenorphine can also be used to treat pain and is 40 times as effective as a painkiller as morphine.
Naloxone is an opioid antagonist that displaces opioid molecules and shuts down opioid receptors. It is most famous for its ability to reverse an opioid overdose when taken nasally or intravenously (as a shot). Naloxone is put into some brands of buprenorphine (like Suboxone and Zubsolv) to deter people from misusing the medication. When taken properly, the naloxone in Suboxone does not get absorbed well by the body. However, if someone tries to inject, smoke or snort the drug then the naloxone will be absorbed enough to cause immediate withdrawal.
Why is Suboxone taken under the tongue?
The simplest answer is something called pharmacokinetics, which is just a fancy way of describing what a drug does once it is inside the body. Pharmacokinetics is why people report drugs working differently for them as compared to their friends. How the drug is absorbed, how it is transported in the blood, how it is broken down by the body’s enzymes and how it is disposed of all determine our experience with a drug.
Drug developers study the pharmacokinetics of each drug for years before it hits the market. That research is how we know that buprenorphine isn’t absorbed well by the lining of our digestive system. When put under the tongue or on the cheek, however, buprenorphine is absorbed well enough to work. A sublingual film or tablet might seem weird but it is the most convenient way to effectively get buprenorphine where it needs to go.
But hold on, what about taking buprenorphine as an injection or nasal spray? Technically, it is possible, but is that really preferable to something that melts in your mouth? Anyway, there are other factors that drove the makers of Suboxone and its competitors to make the product they did. There actually is an injectable form of buprenorphine called Sublocade. Similar to Vivitrol, Sublocade is a once monthly injection under the skin the continuously releases buprenorphine until the next injection. Other formulations of buprenorphine exist, but they are approved by the FDA to treat pain and not addiction.
The biggest reason why you don’t see intranasal or injectable buprenorphine (other than Sublocade) for addiction treatment is misuse potential. There is a deep history of misinformation surrounding addiction that still impacts how we treat it today. Before 2000, the Harrison Narcotics Tax Act of 1912 prevented people with an addiction from being prescribed narcotics such as opioids. This is a byproduct of the arcane idea that addiction was not a disease. It took Congress close to a century to create a partial fix in the form of the Drug Addiction Treatment Act of 2000. While DATA 2000 allowed clinicians with a special waiver the ability to prescribe Suboxone to patients with opioid use disorder, there was still a misplaced belief among policymakers, public health professionals and addiction treatment circles that treatment with Suboxone is tantamount to switching out one addiction for another.
While the hysteria over medication-assisted treatment is lifting, it is impossible to deny that some people do misuse Suboxone. That is why naloxone is added to many buprenorphine products and why people on Suboxone for opioid use disorder are put under strict regiments and monitoring by their care providers. As I mentioned earlier, while naloxone is harmless when taken orally, it can cause adverse reactions if taken by injection or through the nose. This is another reason why injectable (other than Sublocade, which must be injected by a clinician) and nasal buprenorphine do not exist as options for people in recovery from opioid use disorder.
Buprenorphine isn’t the only treatment available for opioid use disorder. Learn more about one person’s experience with buprenorphine and methadone, the other opioid used to treat addiction. Workit Health offers both buprenorphine and naltrexone for opioid addiction, and we have a detailed comparison of both medications.
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Ali Safawi is a Workit Health associate in Michigan. He will be graduating from the University of Michigan with a BA in Community and Global Public Health. His interests include mental health, substance use and healthcare reform.