Norbuprenorphine is a major
active metabolite An active metabolite is an active form of a drug after it has been processed by the body.
Metabolites of drugs
An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body ...
of the
opioid modulator buprenorphine
Buprenorphine is an opioid used to treat opioid use disorder, acute pain, and chronic pain. It can be used under the tongue (sublingual), in the cheek (buccal), by injection (intravenous and subcutaneous), as a skin patch (transdermal), ...
. It is a
μ-opioid,
δ-opioid, and
nociceptin receptor
The nociceptin opioid peptide receptor (NOP), also known as the nociceptin/orphanin FQ (N/OFQ) receptor or kappa-type 3 opioid receptor, is a protein that in humans is encoded by the ''OPRL1'' (opioid receptor-like 1) gene. The nociceptin receptor ...
full agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
,
and a
κ-opioid receptor
The κ-opioid receptor or kappa opioid receptor, abbreviated KOR or KOP, is a G protein-coupled receptor that in humans is encoded by the ''OPRK1'' gene. The KOR is coupled to the G protein Gi/G0 and is one of four related receptors that bind op ...
partial agonist
In pharmacology, partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist. They may also be considered ligands which display both agonistic and antagonistic e ...
.
In rats, unlike buprenorphine, norbuprenorphine produces marked
respiratory depression
Hypoventilation (also known as respiratory depression) occurs when ventilation is inadequate (''hypo'' meaning "below") to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapnia ...
but with very little
antinociceptive
Nociception (also nocioception, from Latin ''nocere'' 'to harm or hurt') is the Somatosensory system, sensory nervous system's process of encoding Noxious stimulus, noxious stimuli. It deals with a series of events and processes required for an org ...
effect.
In explanation of these properties, norbuprenorphine has been found to be a high affinity
P-glycoprotein
P-glycoprotein 1 (permeability glycoprotein, abbreviated as P-gp or Pgp) also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1) or cluster of differentiation 243 (CD243) is an important protein ...
substrate, and in accordance, shows very limited
blood-brain-barrier penetration.
See also
*
Norbuprenorphine-3-glucuronide
Norbuprenorphine-3-glucuronide (N3G) is a major active metabolite of the opioid modulator buprenorphine. It has affinity for the κ-opioid receptor (Ki = 300 nM) and the nociceptin receptor (Ki = 18 μM), but not for the μ- or δ-opioid recept ...
*
Buprenorphine-3-glucuronide
Buprenorphine-3-glucuronide (B3G) is a major active metabolite of the opioid modulator buprenorphine. It has affinity for the μ-opioid receptor (Ki = 4.9 (± 2.7) pM), δ-opioid receptor (Ki = 270 nM), and nociceptin receptor (Ki = 36 μM), but ...
*
Loperamide
Loperamide, sold under the brand name Imodium, among others,Drugs.co Page accessed September 4, 2015 is a medication used to decrease the frequency of diarrhea. It is often used for this purpose in inflammatory bowel disease and short bowel syn ...
*
Noroxymorphone
Noroxymorphone is an opioid which is both a metabolite of oxymorphone and oxycodone and is manufactured specifically as an intermediate in the production of narcotic antagonists such as naltrexone and others. It is a potent agonist of the μ-opi ...
References
4,5-Epoxymorphinans
Phenols
Tertiary alcohols
Ethers
Kappa-opioid receptor agonists
Mu-opioid receptor agonists
Delta-opioid receptor agonists
Nociceptin receptor agonists
Opioid metabolites
Peripherally selective drugs
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