Names | |
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Other names M6G | |
Identifiers | |
3D model (JSmol) | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.161.871 |
MeSH | Morphine-6-glucuronide |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C23H27NO9 | |
Molar mass | 461.46 g/mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Morphine-6-glucuronide (M6G) is a major active metabolite of morphine. M6G is formed from morphine by the enzyme UGT2B7. [1] It has analgesic effects roughly half that of morphine. [2] M6G can accumulate to toxic levels in kidney failure. [3] [4]
This analgesic activity of M6G (in animals) was first noted by Yoshimura. [5]
Subsequent work at St Bartholomew's Hospital, London in the 1980s, [6] using a sensitive and specific high-performance liquid chromatography assay, [7] accurately defined for the first time the metabolism of morphine, and the abundance of this metabolite (along with morphine-3-glucuronide, [8] considered an inactive metabolite).
It was postulated that kidney impairment would result in accumulation of the kidney-excreted active agent M6G, leading to potentially fatal toxicity such as respiratory depression. The frequent use of morphine in critically ill patients, and the common occurrence of kidney failure in this group implied that M6G accumulation could be a common, but previously unanticipated problem. The first studies demonstrated massive levels of M6G in 3 patients with kidney failure, which resolved as kidney function returned. [3] Accumulation of M3G and M6G also decreased with return of kidney function after kidney transplantation. [4]
A key step in defining the importance of M6G in humans came in 1992 when the substance was artificially synthesised and administered to patients with pain, the majority of whom described pain relief. [9]
Oxycodone, sold under the brand name Roxicodone and OxyContin among others, is a semi-synthetic opioid used medically for the treatment of moderate to severe pain. It is highly addictive and is a commonly abused drug. It is usually taken by mouth, and is available in immediate-release and controlled-release formulations. Onset of pain relief typically begins within fifteen minutes and lasts for up to six hours with the immediate-release formulation. In the United Kingdom, it is available by injection. Combination products are also available with paracetamol (acetaminophen), ibuprofen, naloxone, naltrexone, and aspirin.
Systemic scleroderma, or systemic sclerosis, is an autoimmune rheumatic disease characterised by excessive production and accumulation of collagen, called fibrosis, in the skin and internal organs and by injuries to small arteries. There are two major subgroups of systemic sclerosis based on the extent of skin involvement: limited and diffuse. The limited form affects areas below, but not above, the elbows and knees with or without involvement of the face. The diffuse form also affects the skin above the elbows and knees and can also spread to the torso. Visceral organs, including the kidneys, heart, lungs, and gastrointestinal tract can also be affected by the fibrotic process. Prognosis is determined by the form of the disease and the extent of visceral involvement. Patients with limited systemic sclerosis have a better prognosis than those with the diffuse form. Death is most often caused by lung, heart, and kidney involvement. The risk of cancer is increased slightly.
Paracetamol, or acetaminophen, is a non-opioid analgesic and antipyretic agent used to treat fever and mild to moderate pain. It is a widely available over-the-counter drug sold under various brand names, including Tylenol and Panadol.
Hydromorphone, also known as dihydromorphinone, and sold under the brand name Dilaudid among others, is a morphinan opioid used to treat moderate to severe pain. Typically, long-term use is only recommended for pain due to cancer. It may be used by mouth or by injection into a vein, muscle, or under the skin. Effects generally begin within half an hour and last for up to five hours. A 2016 Cochrane review found little difference in benefit between hydromorphone and other opioids for cancer pain.
Uremia is the condition of having high levels of urea in the blood. Urea is one of the primary components of urine. It can be defined as an excess in the blood of amino acid and protein metabolism end products, such as urea and creatinine, which would normally be excreted in the urine. Uremic syndrome can be defined as the terminal clinical manifestation of kidney failure. It is the signs, symptoms and results from laboratory tests which result from inadequate excretory, regulatory, and endocrine function of the kidneys. Both uremia and uremic syndrome have been used interchangeably to denote a very high plasma urea concentration that is the result of renal failure. The former denotation will be used for the rest of the article.
Pethidine, also known as meperidine and sold under the brand name Demerol among others, is a fully synthetic opioid pain medication of the phenylpiperidine class. Synthesized in 1938 as a potential anticholinergic agent by the German chemist Otto Eisleb, its analgesic properties were first recognized by Otto Schaumann while working for IG Farben, in Germany. Pethidine is the prototype of a large family of analgesics including the pethidine 4-phenylpiperidines, the prodines, bemidones, and others more distant, including diphenoxylate and analogues.
Glucuronic acid is a uronic acid that was first isolated from urine. It is found in many gums such as gum arabic, xanthan, and kombucha tea and is important for the metabolism of microorganisms, plants and animals.
Interstitial nephritis, also known as tubulointerstitial nephritis, is inflammation of the area of the kidney known as the renal interstitium, which consists of a collection of cells, extracellular matrix, and fluid surrounding the renal tubules. It is also known as intestinal nephritis because the clinical picture may in some cases of acute pyelonephritis include mesenteric lymphadenitis. More specifically, in case of recurrent urinary tract infection, secondary infection can spread to adjacent intestine. In addition to providing a scaffolding support for the tubular architecture, the interstitium has been shown to participate in the fluid and electrolyte exchange as well as endocrine functions of the kidney.
Analgesic nephropathy is injury to the kidneys caused by analgesic medications such as aspirin, bucetin, phenacetin, and paracetamol. The term usually refers to damage induced by excessive use of combinations of these medications, especially combinations that include phenacetin. It may also be used to describe kidney injury from any single analgesic medication.
6-Monoacetylmorphine is an opioid and also one of three active metabolites of heroin (diacetylmorphine), the others being morphine and the much less active 3-monoacetylmorphine (3-MAM).
Calciphylaxis, also known as calcific uremic arteriolopathy (CUA) or “Grey Scale”, is a rare syndrome characterized by painful skin lesions. The pathogenesis of calciphylaxis is unclear but believed to involve calcification of the small blood vessels located within the fatty tissue and deeper layers of the skin, blood clots, and eventual death of skin cells due to lack of blood flow. It is seen mostly in people with end-stage kidney disease but can occur in the earlier stages of chronic kidney disease and rarely in people with normally functioning kidneys. Calciphylaxis is a rare but serious disease, believed to affect 1-4% of all dialysis patients. It results in chronic non-healing wounds and indicates poor prognosis, with typical life expectancy of less than one year.
UGT2B7 (UDP-Glucuronosyltransferase-2B7) is a phase II metabolism isoenzyme found to be active in the liver, kidneys, epithelial cells of the lower gastrointestinal tract and also has been reported in the brain. In humans, UDP-Glucuronosyltransferase-2B7 is encoded by the UGT2B7 gene.
Nicomorphine is the 3,6-dinicotinate ester of morphine. It is a strong opioid agonist analgesic two to three times as potent as morphine with a side effect profile similar to that of dihydromorphine, morphine, and diamorphine.
Codeine is an opiate and prodrug of morphine mainly used to treat pain, coughing, and diarrhea. It is also commonly used as a recreational drug. It is found naturally in the sap of the opium poppy, Papaver somniferum. It is typically used to treat mild to moderate degrees of pain. Greater benefit may occur when combined with paracetamol (acetaminophen) or a nonsteroidal anti-inflammatory drug (NSAID) such as aspirin or ibuprofen. Evidence does not support its use for acute cough suppression in children. In Europe, it is not recommended as a cough medicine for those under 12 years of age. It is generally taken by mouth. It typically starts working after half an hour, with maximum effect at two hours. Its effects last for about four to six hours. Codeine exhibits abuse potential similar to other opioid medications, including a risk of addiction and overdose.
Morphine-3-glucuronide is a metabolite of morphine produced by UGT2B7. It is not active as an opioid agonist, but does have some action as a convulsant, which does not appear to be mediated through opioid receptors, but rather through interaction with glycine and/or GABA receptors. As a polar compound, it has a limited ability to cross the blood–brain barrier, but kidney failure may lead to its accumulation and result in seizures. Probenecid and inhibitors of P-glycoprotein can enhance uptake of morphine-3-glucuronide and, to a lesser extent, morphine-6-glucuronide. Reported side effects related to the accumulation of this metabolite include convulsions, agitation, hallucinations, hyperalgesia, and coma.
An equianalgesic chart is a conversion chart that lists equivalent doses of analgesics. Equianalgesic charts are used for calculation of an equivalent dose between different analgesics. Tables of this general type are also available for NSAIDs, benzodiazepines, depressants, stimulants, anticholinergics and others.
An opiate is an alkaloid substance derived from opium. It differs from the similar term opioid in that the latter is used to designate all substances, both natural and synthetic, that bind to opioid receptors in the brain. Opiates are alkaloid compounds naturally found in the opium poppy plant Papaver somniferum. The psychoactive compounds found in the opium plant include morphine, codeine, and thebaine. Opiates have long been used for a variety of medical conditions, with evidence of opiate trade and use for pain relief as early as the eighth century AD. Most opiates are considered drugs with moderate to high abuse potential and are listed on various "Substance-Control Schedules" under the Uniform Controlled Substances Act of the United States of America.
Codeine-6-glucuronide (C6G) is a major active metabolite of codeine and may be responsible for as much as 60% of the analgesic effects of codeine. C6G exhibits decreased immunosuppressive effects compared to codeine. During its metabolism, codeine is conjugated with glucuronic acid by the enzyme UDP-Glucuronosyltransferase-2B7 (UGT2B7) to form codeine-6-glucuronide.
Benzhydrocodone (INN) is an opioid prodrug of the morphinan class. Its chemical structure consists of hydrocodone coupled with benzoic acid. Benzhydrocodone itself is inactive and acts as a prodrug to hydrocodone upon cleavage of the benzoate portion of the molecule.
Ertugliflozin, sold under the brand name Steglatro, is a medication used for the treatment of type 2 diabetes.