Buprenorphine Fact Card
What is buprenorphine?
Derived from thebaine,  buprenorphine is a semi-synthetic opiate, belonging to the broader opioid drug family. Classified as a narcotic analgesic, buprenorphine is available in the United States only by prescription and for use by licensed medical facilities. Buprenorphine is dispensed primarily for treating opioid use disorder (OUD) during medication-assisted therapy (MAT) — most notably under the brand name Suboxone. Less commonly, buprenorphine might be prescribed as an analgesic for treating pain. Buprenorphine is available in monoproduct form and in combination with naloxone to discourage misuse by injection. Prescription buprenorphine is found in a wide variety of forms: as oral tablets, sublingual or buccal films, transdermal patches, subdermal implants, and injectable forms. Street buprenorphine is licitly manufactured buprenorphine that is either a diverted prescription or the subject of another form of diversion.
What is medication-assisted therapy?
Medication-assisted therapy (MAT) pertaining to the treatment of opioid use disorder (OUD) involves replacing the use of shorter acting and highly addictive opioids, such as heroin or oxycodone, with controlled and medically-supervised dosing of a longer acting, less addictive, and less euphoric opioid — typically buprenorphine or methadone.  This approach allows the opioid-addicted patient to avoid the persistent cravings and roller-coaster effects associated with short-acting opioid use, in addition to the debilitating withdrawal symptoms associated with cold-turkey abstinence. MAT allows for the patient to reach a level of stability, where patient and clinician may choose to continue with opioid maintenance treatment or pursue withdrawal management.  With any approach to treating opioid use disorder, concurrent psychosocial treatment is viewed as an essential cornerstone. 
What are the effects of buprenorphine?
Buprenorphine possesses mixed properties of both an opioid partial agonist and an opioid antagonist, making it effective at curbing cravings and withdrawal symptoms in users who have developed physical dependence on opioids. For those with no physical dependence (opioid naive), buprenorphine produces some level of euphoria or "high" — though less than other opioids, such as heroin or oxycodone. For those with physical dependence, buprenorphine produces only minimal levels of euphoria — and is also effective at impeding the euphoric effects of other opioids.  Due to these factors, buprenorphine is commonly used as an opioid replacement drug during medication-assisted therapy (MAT). However, similar to the opioids it is intended to replace, buprenorphine is prone to abuse and is highly addictive, capable of producing harsh withdrawal symptoms when abstinence is attempted by users with physical dependence on buprenorphine or other opioids. 
Buprenorphine Diversion and Abuse
Due to its relative safety, availability, and low price in comparison with many other opioids, buprenorphine is a prime target for diversion, illicit use, and misuse.  Because its euphoric effects are less apparent than that of most other opioids, buprenorphine is unlikely to be a drug user's first drug of choice. However, when the opioid addicted have difficulty procuring their preferred opioid product, diverted buprenorphine often serves as the stand-in. 
When oral buprenorphine is taken sublingually or buccally as indicated, bioavailability is approximately 30%,  compared to near 100% when used intravenously.  As a result, many buprenorphine users turn to injecting their supply. In an effort to discourage misuse by injection, drug makers have combined buprenorphine with the opioid antagonist naloxone in the following products: Bunavail, Cassipa, Suboxone, Zubsolv, and many generic labels. If such buprenorphine/naloxone coformulations are injected by individuals physically dependent on opioids, naloxone's antagonistic effects are deployed, blocking the opioid effects of the buprenorphine and producing unwanted withdrawal symptoms.  This design has demonstrated mixed success. While many users are heavily discouraged by the unpleasant results, many report little to no side effects when injecting buprenorphine/naloxone coformulations.
Urine Testing for Buprenorphine
Buprenorphine urine tests target buprenorphine, with possible cross-reactivity for buprenorphine metabolites, including norbuprenorphine, buprenorphine 3-B-D-glucuronide (B3G), and norbuprenorphine 3-B-D-glucuronide (NB3G). Buprenorphine is present as free unchanged parent drug in the urine of those ingesting buprenorphine.  Norbuprenorphine is present as a metabolite in the urine of those ingesting buprenorphine.  B3G is prominent as a metabolite in the urine of those ingesting buprenorphine.  NB3G is prominent as a metabolite in the urine of those ingesting buprenorphine. 
Buprenorphine urine tests detect buprenorphine use primarily due to their cross-reactivity with the metabolites buprenorphine 3-B-D-glucuronide (B3G) and norbuprenorphine 3-B-D-glucuronide (NB3G). Although urine tests for buprenorphine do target buprenorphine, it's important to note that conjugated buprenorphine in the form of B3G and conjugated norbuprenorphine in the form of NB3G appear in significantly higher concentrations in the urine of those ingesting buprenorphine. So, sensitivity to B3G and NB3G, rather than sensitivity to buprenorphine, will have a far greater impact on an assay's ability to detect the use of buprenorphine. Following a buprenorphine dose, approximately 11% is recovered in the urine as norbuprenorphine 3-B-D-glucuronide (NB3G), 9.4% as buprenorphine 3-B-D-glucuronide (B3G), 2.7% as free norbuprenorphine, and 1% as free buprenorphine.