buprenorphine

Buprenorphine is a long-acting opioid medication used primarily to treat opioid use disorder and, in some cases, chronic pain. It is a partial agonist at the mu-opioid receptor with high receptor affinity, which provides analgesia and withdrawal symptom relief at lower maximal effects. Its ceiling effect on respiratory depression reduces the risk of fatal overdose when used as directed, though risk remains when combined with other depressants or taken improperly. The high receptor affinity also means buprenorphine can block or lessen the effects of other opioids.

In opioid use disorder, buprenorphine is used as a maintenance therapy to reduce cravings and illicit opioid use and to lower overdose risk. A common formulation combines buprenorphine with naloxone to deter misuse by injection; naloxone has limited sublingual bioavailability but can precipitate withdrawal if injected. For chronic pain, buprenorphine is available in formulations designed for long-term analgesia, including sublingual and transdermal products and, in some settings, injectable forms.

Pharmacokinetics and administration vary by formulation. Sublingual tablets or films are commonly used for addiction treatment, with onset within about 30 to 60 minutes and a long duration of action. Transdermal patches provide another route for analgesia. Buprenorphine is primarily metabolized by the liver (glucuronidation) and excreted in urine and feces. It should be used with caution in hepatic impairment and is contraindicated in certain hypersensitivity states. Initiation requires monitoring for precipitated withdrawal if the patient has recently used full opioid agonists.

Common adverse effects include constipation, nausea, headache, dizziness, and sweating. Dependence and withdrawal can occur with discontinuation. Buprenorphine is widely used in opioid dependence treatment and is listed on multiple national and international essential medicines lists.