Drug Groups

illicit; approved; investigational

Description

A derivative of the opioid alkaloid thebaine that is a more potent and longer lasting analgesic than morphine. It appears to act as a partial agonist at mu and kappa opioid receptors and as an antagonist at delta receptors. The lack of delta-agonist activity has been suggested to account for the observation that buprenorphine tolerance may not develop with chronic use. [PubChem]

Indication

For the treatment of moderate to severe pain, peri-operative analgesia, and opioid dependence.

Pharmacology

Buprenorphine is a synthetic opioid analgesic and thebaine derivative, with a longer duration of action than morphine. Buprenorphine interacts predominately with the opioid mu-receptor. These mu-binding sites are discretely distributed in the human brain, spinal cord, and other tissues. In clinical settings, buprenorphine exerts its principal pharmacologic effects on the central nervous system. Its primary actions of therapeutic value are analgesia and sedation. Buprenorphine may increase the patient's tolerance for pain and decrease the perception of suffering, although the presence of the pain itself may still be recognized. In addition to analgesia, alterations in mood, euphoria and dysphoria, and drowsiness commonly occur. Buprenorphine depresses the respiratory centers, depresses the cough reflex, and constricts the pupils.

Toxicity

Manifestations of acute overdose include pinpoint pupils, sedation, hypotension, respiratory depression and death.

Affected Organisms

Biotransformation

Hepatic. Buprenorphine undergoes both N-dealkylation to norbuprenorphine and glucuronidation. The N-dealkylation pathway is mediated by cytochrome P-450 3A4 isozyme. Norbuprenorphine, an active metabolite, can further undergo glucuronidation.

Absorption

31% bioavailability (sublingual)

Half Life

37 hours

Protein Binding

96%

Elimination

Buprenorphine, in common with morphine and other phenolic opioid analgesics, is metabolized by the liver and its clearance is related to hepatic blood flow.

References

External Links