Buprenorphine

• Opioid Use Disorder
• Chronic Pain Management
• Medication-Assisted Treatment
• Opioid Dependence

Buprenorphine is a partial opioid agonist used for the treatment of opioid use disorder and chronic pain management. This medication provides effective treatment for opioid dependence while having a unique pharmacological profile that limits its abuse potential and reduces overdose risk.

Mechanism of Action

Buprenorphine is a partial agonist at the mu-opioid receptor and an antagonist at the kappa-opioid receptor. As a partial agonist, it produces opioid effects (analgesia, euphoria) but with a ceiling effect—increasing doses beyond a certain point do not increase effects. This ceiling effect limits respiratory depression risk compared to full agonists. Buprenorphine has very high binding affinity for mu-receptors, allowing it to displace other opioids and prevent their effects. Its slow dissociation from receptors contributes to its long duration of action. The kappa antagonism may contribute to antidepressant effects and reduced dysphoria.

Available Formulations

Buprenorphine is available in multiple formulations: sublingual tablets (2 mg, 8 mg), buccal film, transdermal patch (for pain), extended-release subcutaneous injection (monthly), and implantable rods (lasting 6 months). For opioid use disorder, sublingual and injectable formulations are preferred. The sublingual tablet must dissolve under the tongue; swallowing reduces bioavailability to approximately 15%. Transdermal patches are used for chronic pain, not addiction treatment.

Medical Uses

Buprenorphine is FDA-approved for the treatment of opioid use disorder (OUD), moderate to severe chronic pain (transdermal patch), and acute pain severe enough to require opioid analgesia (buccal film). For OUD, it reduces cravings, prevents withdrawal symptoms, and blocks the effects of other opioids. Unlike methadone, qualified physicians can prescribe buprenorphine from office-based settings, improving treatment access. It is a preferred medication for opioid use disorder due to its safety profile and effectiveness.

Dosing Guidelines

For opioid use disorder using sublingual tablets, induction typically starts at 2-4 mg, with additional doses of 2-4 mg given at intervals until withdrawal symptoms are controlled (usually 8-16 mg on day 1). Maintenance doses typically range from 16-24 mg daily. For chronic pain using transdermal patches, the starting dose is typically 5 mcg/hour, applied weekly. Buprenorphine should be initiated when the patient is in mild to moderate opioid withdrawal to prevent precipitated withdrawal. Extended-release injectable formulations provide monthly or weekly dosing options.

Important Safety Information

Buprenorphine carries a boxed warning regarding serious, life-threatening respiratory depression, especially when used with benzodiazepines or other CNS depressants, and for neonatal opioid withdrawal syndrome when used during pregnancy. Precipitated withdrawal can occur if administered to patients physically dependent on full opioid agonists who are not in withdrawal. The medication is a Schedule III controlled substance. Hepatotoxicity has been reported. Orthostatic hypotension and QT prolongation may occur.

Drug Interactions

CNS depressants (benzodiazepines, alcohol, other opioids, sedatives) may cause profound sedation, respiratory depression, and death. CYP3A4 inhibitors (ketoconazole, ritonavir) may increase buprenorphine levels. CYP3A4 inducers (rifampin, carbamazepine, phenytoin) may decrease levels. Buprenorphine can precipitate withdrawal in patients dependent on full opioid agonists. Naltrexone will block buprenorphine effects; adequate washout periods are required when switching between medications.

Special Populations

Buprenorphine use during pregnancy can cause neonatal opioid withdrawal syndrome; however, the benefits of treatment may outweigh the risks, and methadone or buprenorphine is recommended over discontinuation for pregnant women with opioid use disorder. Buprenorphine is excreted in breast milk; breastfeeding women on stable buprenorphine doses may breastfeed with monitoring. Safety in pediatric patients has not been established for OUD. Elderly patients may require lower doses. Severe hepatic impairment requires dose adjustment; the medication should be used with caution in moderate impairment.