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Wednesday, August 1, 2018

A single-molecule room-temperature transistor made from 14 atoms

September 1, 2017
Original link:  http://www.kurzweilai.net/a-single-molecule-room-temperature-transistor-made-from-14-atoms
Columbia researchers wired a single molecule consisting of 14 atoms connected to two gold electrodes to show that it performs as a transistor at room temperature. (credit: Bonnie Choi/Columbia University)

Columbia Engineering researchers have taken a key step toward atomically precise, reproducible transistors made from single molecules and operating at room temperature — a major goal in the field of molecular electronics.

The team created a two-terminal transistor with a diameter of about 0.5 nanometers and core consisting of just 14 atoms. The device can reliably switch from insulator to conductor when charge is added or removed, one electron at a time (known as “current blockade”).*

The research was published in the journal Nature Nanotechnology.

Controllable structure with atomic precision

“With these molecular clusters, we have complete control over their structure with atomic precision and can change the elemental composition and structure in a controllable manner to elicit certain electrical response,” says Latha Venkataraman, leader of the Columbia research team.

The researchers plan to design improved molecular cluster systems with better electrical performance (such as higher on/off current ratio and different accessible states) and increase the number of atoms in the cluster core, while maintaining the atomic precision and uniformity of the compound.

Other studies have created quantum dots to produce similar effects, but the dots are much larger and not uniform in size, and the results have not been reproducible. The ultimate size reduction would be single-atom transistors, but they require ultra-cold temperatures (minus 196 degrees Celsius in this case, for example).

The single molecule’s 14-atom core structure comprises cobalt (blue) and sulfur (yellow) atoms (left) and ethyl-4-(methylthio)phenyl phosphine atoms, used to wire the cluster into a junction (right). (credit: Bonnie Choi/Columbia University)

* The researchers used a scanning tunneling microscope technique that they pioneered to make junctions comprising a single cluster connected to the two gold electrodes, which enabled them to characterize its electrical response as they varied the applied bias voltage. The technique allows them to fabricate and measure thousands of junctions with reproducible transport characteristics. The team worked with small inorganic molecular clusters that were identical in shape and size, so they knew exactly — down to the atomic scale — what they were measuring. The team evaluated the performance of the diode by the on/off ratio — the ratio between the current flowing through the device when it is switched on and the residual current still present in its “off” state. At room temperature, they observed a high on/off ratio of about 600 in single-cluster junctions, higher than any other single-molecule devices measured to date.


Abstract of Room-temperature current blockade in atomically defined single-cluster junctions

Fabricating nanoscopic devices capable of manipulating and processing single units of charge is an essential step towards creating functional devices where quantum effects dominate transport characteristics. The archetypal single-electron transistor comprises a small conducting or semiconducting island separated from two metallic reservoirs by insulating barriers. By enabling the transfer of a well-defined number of charge carriers between the island and the reservoirs, such a device may enable discrete single-electron operations. Here, we describe a single-molecule junction comprising a redox-active, atomically precise cobalt chalcogenide cluster wired between two nanoscopic electrodes. We observe current blockade at room temperature in thousands of single-cluster junctions. Below a threshold voltage, charge transfer across the junction is suppressed. The device is turned on when the temporary occupation of the core states by a transiting carrier is energetically enabled, resulting in a sequential tunnelling process and an increase in current by a factor of ∼600. We perform in situ and ex situ cyclic voltammetry as well as density functional theory calculations to unveil a two-step process mediated by an orbital localized on the core of the cluster in which charge carriers reside before tunnelling to the collector reservoir. As the bias window of the junction is opened wide enough to include one of the cluster frontier orbitals, the current blockade is lifted and charge carriers can tunnel sequentially across the junction.

Fentanyl

From Wikipedia, the free encyclopedia
Fentanyl
Fentanyl2DCSD.svg
Fentanyl-xtal-3D-balls.png
Clinical data
Trade namesActiq, Duragesic, Fentora, others
AHFS/Drugs.comMonograph
License data
Pregnancy
category
  • AU: C
  • US: C (Risk not ruled out)
Dependence
liability
Very high
Routes of
administration
Buccal, epidural, IM, IT, IV, sublingual, skin patch
Drug classOpioid
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability92% (transdermal)
89% (intranasal)
50% (buccal)
33% (ingestion)
Protein binding80–85%
Metabolismhepatic, primarily by CYP3A4
Onset of action5 minutes[1]
Elimination half-lifeIV: 6 mins (T1/2 α)
1 hours (T1/2 β)
16 hours (T1/2 ɣ)
Intranasal: 6.5 hours
Transdermal: 20–27 hours[2]
Sublingual/buccal (single dose): 2.6–13.5 hours[2]
Duration of actionIV: 30–60 minutes[3][1]
ExcretionMostly urinary (metabolites, <10 class="reference" drug="" id="cite_ref-AHFS2017_2-2" sup="" unchanged="">[2]

Identifiers
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
ECHA InfoCard
100.006.468 Edit this at Wikidata
Chemical and physical data
Formula
C22H28N2O
Molar mass
336.471 g/mol
3D model (JSmol)
Melting point
87.5 °C (189.5 °F)

Fentanyl (also spelled fentanil) is an opioid used as a pain medication and together with other medications for anesthesia. Fentanyl is also made illegally and used as a recreational drug, often mixed with heroin or cocaine. It has a rapid onset and effects generally last less than an hour or two. Medically, fentanyl is used by injection, as a patch on the skin, as a nasal spray, or in the mouth.

Common side effects include vomiting, constipation, sedation, confusion, hallucinations, and injuries related to poor coordination.[2][5] Serious side effects may include decreased breathing (respiratory depression), serotonin syndrome, low blood pressure, addiction, or coma.[2][5] In 2016, more than 20,000 deaths occurred in the United States due to overdoses of fentanyl and fentanyl analogues, half of all reported opioid related deaths.[6][7] Fentanyl works primarily by activating μ-opioid receptors.[2] It is around 100 times stronger than morphine, and some analogues such as carfentanil are around 10,000 times stronger.[8]

Fentanyl was first made by Paul Janssen in 1960 and approved for medical use in the United States in 1968.[2][9]In 2015, 1,600 kilograms (3,500 lb) were used in healthcare globally.[10] As of 2017, fentanyl was the most widely used synthetic opioid in medicine.[11] Fentanyl patches are on the WHO List of Essential Medicines, the most effective and safe medicines needed in a health system.[12] For a 100 microgram vial, the average wholesale cost in the developing world is US$0.66 (2015)[13] while in the USA the price is US$0.49 (2017) for that amount.[14]

Medical uses

Intravenous and intrathecal

Intravenous fentanyl is often used for anaesthesia and analgesia. During anaesthesia it is often used along with a hypnotic agent like propofol. It is also administered in combination with a benzodiazepine, such as midazolam, to produce sedation for procedures such as endoscopy, cardiac catheterization, and oral surgery, or in emergency rooms.[15][16] It is also used in the management of chronic pain including cancer pain.[17]

Fentanyl is sometimes given intrathecally as part of spinal anaesthesia or epidurally for epidural anaesthesia and analgesia. Because of fentanyl's high lipid solubility, its effects are more localized than morphine, and some clinicians prefer to use morphine to get a wider spread of analgesia.[18]

Patches

A fentanyl transdermal patch with a release rate of 12 micrograms / hour, on a person's arm.

Fentanyl transdermal patches (Duragesic) are used in chronic pain management. The patches work by slowly releasing fentanyl through the skin into the bloodstream over 48 to 72 hours, allowing for long-lasting pain management.[19] Dosage is based on the size of the patch, since, in general, the transdermal absorption rate is constant at a constant skin temperature.[19] Rate of absorption is dependent on a number of factors. Body temperature, skin type, amount of body fat, and placement of the patch can have major effects. The different delivery systems used by different makers will also affect individual rates of absorption. Under normal circumstances, the patch will reach its full effect within 12 to 24 hours; thus, fentanyl patches are often prescribed with a fast-acting opioid (such as morphine or oxycodone) to handle breakthrough pain.[19]

It is unclear if fentanyl gives long-term pain relief to people with neuropathic pain.[20]

In palliative care, transdermal fentanyl has a definite, but limited, role for:
  • people already stabilized on other opioids who have persistent swallowing problems and cannot tolerate other parenteral routes such as subcutaneous administration.
  • people with moderate to severe kidney failure.
  • troublesome side effects of oral morphine, hydromorphone, or oxycodone.[citation needed]
Care must be taken to guard against the application of external heat sources (such as direct sunlight, heating pads, etc.) which in certain circumstances can trigger the release of too much medication and cause life-threatening complications.

Duragesic was first approved by the College ter Beoordeling van Geneesmiddelen, the Medicines Evaluation Board in the Netherlands, on July 17, 1995, as 25, 50, 75 and 100 µg/h formulations after a set of successful clinical trials, and on October 27, 2004, the 12 µg/h (actually 12.5 µg/h) formulation was approved as well. On January 28, 2005, the U.S. Food and Drug Administration approved first-time generic formulations of 25, 50, 75, and 100 µg/h fentanyl transdermal systems (made by Mylan Technologies, Inc.; brand name Duragesic, made by Alza Corp.) through an FTC consent agreement derailing the possibility of a monopoly in the treatment of breakthrough chronic pain by Alza Corp. In some cases, physicians instruct people to apply more than one patch at a time, giving a much wider range of possible dosages. For example, a person may be prescribed a 37.5 µg dosage by applying one 12.5 µg patch and one 25 µg patch simultaneously, or contingent on the large size of the (largest) 100 μg/h patch, multiple patches are commonly prescribed for doses exceeding 100μg/h, such as two 75 μg/h patches worn to afford a 150 μg/h dosage regimen. Although the commonly referred to dosage rates are 12/25/50/75/100 µg/h, the "12 µg" patch actually releases 12.5 µg/h.[21] It is designed to release half the dose of the 25 µg/h dose patch.

As of July 2009, construction of the Duragesic patch had been changed from the gel pouch and membrane design to "a drug-in-adhesive matrix designed formulation", as described in the prescribing information.[21] This construction makes illicit use of the fentanyl more difficult.

Storage and disposal

The fentanyl patch is one of a small number of medications that may be especially harmful, and in some cases fatal, with just one dose, if used by someone other than the person for whom the medication was prescribed.[22] Unused fentanyl patches should be kept in a secure location that is out of children’s sight and reach, such as a locked cabinet.

When patches cannot be disposed of through a medication take-back program, flushing is recommended for fentanyl patches because it is the fastest and surest way to remove them from the home so they cannot harm children, pets and others who were not intended to use them.[22][23][24]

Intranasal

The bioavailability of intranasal fentanyl is about 70–90%, but with some imprecision due to clotted nostrils, pharyngeal swallow and incorrect administration. For both emergency and palliative use, intranasal fentanyl is available in doses of 50, 100, and 200 µg. In emergency medicine, safe administration of intranasal fentanyl with a low rate of side effects and a promising pain reducing effect was demonstrated in a prospective observational study in about 900 out-of-hospital patients.[25]

In children, intranasal fentanyl is useful for the treatment of moderate and severe pain and is well tolerated.[26]

Sublingual

Abstral dissolves quickly and is absorbed through the sublingual mucosa to provide rapid analgesia.[27] Fentanyl is a highly lipophilic compound,[27][28] which is well absorbed sublingually and generally well tolerated.[27] Such forms are particularly useful for breakthrough cancer pain episodes, which are often rapid in onset, short in duration and severe in intensity.[29]

Lozenges

Package and example of fentanyl lollipop (brand: Actiq), 400 micrograms.

Fentanyl lozenges (Actiq) are a solid formulation of fentanyl citrate on a stick in the form of a lollipop that dissolves slowly in the mouth for transmucosal absorption. These lozenges are intended for opioid-tolerant individuals and are effective in treating breakthrough cancer pain.[30] It has also been used for breakthrough pain for people with not cancer related pain, but this application is controversial.[31] The unit is a berry-flavoured lozenge on a stick swabbed on the mucosal surfaces inside the mouth—inside of the cheeks, under and on the tongue and gums—to release the fentanyl quickly into the system. It is most effective when the lozenge is consumed within 15 minutes. About 25% of the medication is absorbed through the oral mucosa, resulting in a fast onset of action, and the rest is swallowed and absorbed in the small intestine, acting more slowly. The lozenge is less effective and acts more slowly if swallowed as a whole, as despite good absorbance from the small intestine there is extensive first-pass metabolism, leading to an oral bioavailability of about 33% as opposed to 50% when used correctly, (25% via the mouth mucosa and 25% via the gut).[30]
Actiq is produced by the pharmaceutical company Cephalon on a plastic stick; this provides the means by which the medication can maintain its placement while it dissolves slowly in the mouth for absorption across the buccal mucosa, in a manner similar to sublingual buprenorphine/naloxone film strips. An Actiq lozenge contains 2 grams of sugar (8 calories).[32][33] Actiq has been linked to dental decay, with some users who had no prior dental issues suffering tooth loss, and in the U.S many users have started their own Facebook pages to educate users about the severe dental issues caused by Actiq fentanyl pops as well as suing Cephalon for damages.[34]

In September 2006, a generic fentanyl lozenge was released by Barr Pharmaceuticals.[35]

USAF Pararescue combat medics in Afghanistan use fentanyl lollipops on combat casualties from IED blasts and other trauma.[36] The stick is taped to a finger and the lozenge put in the cheek of the person. When enough fentanyl has been absorbed, the (sedated) person generally let the lollipop fall from the mouth, indicating sufficient analgesia and somewhat reducing the likelihood of overdose and associated risks.[36]

Other

Some routes of administration such as nasal sprays and inhalers generally result in faster onset of high blood levels, which can provide more immediate analgesia but also more severe side effects, especially in overdose. The much higher cost of some of these appliances may not be justified by marginal benefit compared with buccal or oral options. Intranasal fentanyl appears to be equally effective as IV morphine and superior to intramuscular morphine for management of acute hospital pain.[37]

A fentanyl patient-controlled transdermal system (PCTS) is under development, which aims to allow people to control administration of fentanyl through the skin to treat postoperative pain.[38]

Adverse effects

Fentanyl's most common side effects (more than 10% of people) include diarrhea, nausea, constipation, dry mouth, somnolence, confusion, asthenia (weakness), sweating, and less frequently (3 to 10% of people) abdominal pain, headache, fatigue, anorexia and weight loss, dizziness, nervousness, hallucinations, anxiety, depression, flu-like symptoms, dyspepsia (indigestion), shortness of breath, hypoventilation, apnoea, and urinary retention. Fentanyl use has also been associated with aphasia.[39]

Despite being a more potent analgesic, fentanyl tends to induce less nausea, as well as less histamine-mediated itching, than morphine.[40]

Sustained release fentany preparations, such as patches, may produce unexpected delayed respiratory depression.[41][42][43]The duration of action of fentanyl has sometimes been underestimated, leading to harm in a medical context.[44][45][46][47] In 2006, the U.S. Food and Drug Administration (FDA) began investigating several respiratory deaths, but doctors in the United Kingdom were not warned of the risks with fentanyl until September 2008.[48] The FDA reported in April 2012 that twelve young children had died and twelve more made seriously ill from separate accidental exposures to fentanyl skin patches.[49]

The precise reason for sudden respiratory depression is unclear, but there are several hypotheses:
  • Saturation of the body fat compartment in people with rapid and profound body fat loss (people with cancer, cardiac or infection-induced cachexia can lose 80% of their body fat).
  • Early carbon dioxide retention causing cutaneous vasodilation (releasing more fentanyl), together with acidosis, which reduces protein binding of fentanyl, releasing yet more fentanyl.
  • Reduced sedation, losing a useful early warning sign of opioid toxicity and resulting in levels closer to respiratory-depressant levels.
Fentanyl has a therapeutic index of 270.[50]

Overdose

US yearly overdose deaths, and some of the drugs involved. Among the more than 64,000 deaths estimated in 2016, the sharpest increase occurred among deaths related to fentanyl and fentanyl analogs (synthetic opioids in the chart) with over 20,000 deaths.[51]
 In July 2014, the Medicines and Healthcare Products Regulatory Agency (MHRA) of the UK issued a warning about the potential for life-threatening harm from accidental exposure to transdermal fentanyl patches, particularly in children,[52] and advised that they should be folded, with the adhesive side in, before being discarded. The patches should be kept away from children, who are most at risk from fentanyl overdose.[53]

Death from fentanyl overdose was declared a public health crisis in Canada in September 2015, and it continues to be a significant public health issue.[54] In 2016, deaths from fatal fentanyl overdoses in British Columbia, Canada, averaged two persons per day.[55] In 2017 the death rate rose over 100% with 368 overdose related deaths in British Columbia between January and April 2017.[56]

Medical examiners concluded that musician Prince died on April 21, 2016, from an accidental fentanyl overdose.[57] Fentanyl was among many substances identified in counterfeit pills recovered from his home, especially some that were mislabeled as Watson 385, a combination of hydrocodone and paracetamol.[57][58] American rapper Lil Peep also died of an accidental fentanyl overdose on November 15, 2017.[59][60] On January 19, 2018, the medical examiner-coroner for the county of Los Angeles announced that Tom Petty died from an accidental drug overdose as a result of mixing medications that included fentanyl, acetyl fentanyl and despropionyl fentanyl (among others). He was reportedly treating "many serious ailments" that included a broken hip.[61]

In the US, Fentanyl caused 20,100 deaths in 2016, a rise of 540% over the past 3 years.[62][51]

Pharmacology

Fentanyl at opioid receptors[63]
Affinities (Ki) Ratio
MOR DOR KOR MOR:DOR:KOR
0.39 nM >1,000 nM 255 nM 1:>2564:654

Fentanyl provides some of the effects typical of other opioids through its agonism of the opioid receptors. Its strong potency in relation to that of morphine is largely due to its high lipophilicity, per the Meyer-Overton correlation. Because of this, it can more easily penetrate the central nervous system.[40]

Detection in biological fluids

Fentanyl may be measured in blood or urine to monitor for abuse, confirm a diagnosis of poisoning, or assist in a medicolegal death investigation. Commercially available immunoassays are often used as initial screening tests, but chromatographic techniques are generally used for confirmation and quantitation. Blood or plasma fentanyl concentrations are expected to be in a range of 0.3–3.0 μg/l in persons using the medication therapeutically, 1–10 μg/l in intoxicated people and 3-300 μg/l in victims of acute overdosage.[64] Spray-mass spectrometry (PS-MS) may be useful for initial testing of samples.[65]

History

Fentanyl was first synthesized by Paul Janssen under the label of his relatively newly formed Janssen Pharmaceutica in 1959.[66] It was developed by screening chemicals similar to pethidine (meperidine) for opioid activity.[67] The widespread use of fentanyl triggered the production of fentanyl citrate (the salt formed by combining fentanyl and citric acid in a 1:1 stoichiometric ratio).[68] Fentanyl citrate entered medical use as a general anaesthetic in 1968, manufactured by McNeil Laboratories under the trade name Sublimaze.[69]

In the mid-1990s, Janssen Pharmaceutica developed and introduced into clinical trials the Duragesic patch, which is a formation of an inert alcohol gel infused with select fentanyl doses, which are worn to provide constant administration of the opioid over a period of 48 to 72 hours. After a set of successful clinical trials, Duragesic fentanyl patches were introduced into medical practice.

Following the patch, a flavoured lollipop of fentanyl citrate mixed with inert fillers was introduced in 1998 under the brand name of Actiq, becoming the first quick-acting formation of fentanyl for use with chronic breakthrough pain.[70]

In 2009, the US Food and Drug Administration approved Onsolis (fentanyl buccal soluble film), a fentanyl drug in a new dosage form for cancer pain management in opioid-tolerant subjects.[71] It uses a medication delivery technology called BEMA (BioErodible MucoAdhesive), a small dissolvable polymer film containing various fentanyl doses applied to the inner lining of the cheek.[71]

Fentanyl has a US DEA ACSCN of 9801 and a 2013 annual aggregate manufacturing quota of 2,108.75 kg, unchanged from the prior year.

Society and culture

Brand names

Brand names include Sublimaze,[39] Actiq, Durogesic, Duragesic, Fentora, Matrifen, Haldid, Onsolis,[72] Instanyl,[73] Abstral,[74] Lazanda[75] and others.[76] Subsys is a sublingual spray of fentanyl manufactured by Insys Therapeutics.[77]

Cost

The wholesale cost in the developing world as of 2015 is between US$0.08 and US$0.81 per 100 microgram vial.[13] In the United States this amount costs about US$0.40 as of 2017.[14] In the United States the patches cost US$11.22 for a 12 µg/hr version and US$8.74 for a 100 µg/hr version.[14]

Legal status

In the UK, fentanyl is classified as a controlled Class A drug under the Misuse of Drugs Act 1971.[78]
In the Netherlands, fentanyl is a List I substance of the Opium Law.

In the U.S., fentanyl is a Schedule II controlled substance per the Controlled Substance Act. Distributors of Abstral are required to implement an FDA-approved risk evaluation and mitigation strategy (REMS) program.[79][80] In order to curb misuse, many health insurers have begun to require precertification and/or quantity limits for Actiq prescriptions.[81][82][83]

Public health advisories

The US Food and Drug Administration (FDA) has issued public health advisories related to fentanyl patch dangers. Among these, in July 2005, the FDA issued a Public Health Advisory,[84] which advised that "deaths and overdoses have occurred in patients using both the brand name product Duragesic and the generic product." In December 2007, as part of this continuing investigation, the FDA issued a second Public Health Advisory[84] stating, "The FDA has continued to receive reports of deaths and life-threatening side effects in patients who use the fentanyl patch. The reports indicate that doctors have inappropriately prescribed the fentanyl patch... In addition, the reports indicate that patients are continuing to incorrectly use the fentanyl patch..."

Recreational use

Fentanyl powder seized by a sheriff.[85]

Illicit use of pharmaceutical fentanyl and its analogues first appeared in the mid-1970s in the medical community and continues in the present. More than 12 different analogues of fentanyl, all unapproved and clandestinely-produced, have been identified in the U.S. drug traffic. The biological effects of the fentanyl analogues are similar to those of heroin, with the exception that many users report a noticeably less euphoric high associated with the drug and stronger sedative and analgesic effects.

Fentanyl analogues may be hundreds of times more potent than heroin. Fentanyl is used orally, smoked, snorted, or injected. Fentanyl is sometimes sold as heroin or oxycodone, sometimes leading to overdoses. Many fentanyl overdoses are initially classified as heroin overdoses.[86] The recreational use is not particularly widespread in the EU with the exception of Tallinn, Estonia, where it has largely replaced heroin. Estonia has the highest rate of 3-methylfentanyl overdose deaths in the EU, due to its high rate of recreational use.[87]

Fentanyl is sometimes sold on the black market in the form of transdermal fentanyl patches such as Duragesic, diverted from legitimate medical supplies. The gel from inside the patches may be ingested or injected.[88]

Another form of fentanyl that has appeared on the streets is the Actiq lollipop formulation. The pharmacy retail price ranges from $15 to $50 per unit based on the strength of the lozenge, with the black market cost ranging from $5 to $25, depending on the dose.[89] The attorneys general of Connecticut and Pennsylvania have launched investigations into its diversion from the legitimate pharmaceutical market, including Cephalon's "sales and promotional practices for Provigil, Actiq and Gabitril".[89]

Non-medical use of fentanyl by individuals without opiate tolerance can be very dangerous and has resulted in numerous deaths.[88] Even those with opiate tolerances are at high risk for overdoses. Like all opioids, the effects of fentanyl can be reversed with naloxone, or other opiate antagonists. Naloxone is increasingly available to the public. Long acting or sustained release opioids may require repeat dosage. Illicitly synthesized fentanyl powder has also appeared on the United States market. Because of the extremely high strength of pure fentanyl powder, it is very difficult to dilute appropriately, and often the resulting mixture may be far too strong and, therefore, very dangerous.

Some heroin dealers mix fentanyl powder with heroin to increase potency or compensate for low-quality heroin. In 2006, illegally manufactured, non-pharmaceutical fentanyl often mixed with cocaine or heroin caused an outbreak of overdose deaths in the United States and Canada, heavily concentrated in the cities of Dayton, Ohio; Chicago; Detroit; and Philadelphia.[90]

Several large quantities of illicitly produced fentanyl have been seized by U.S. law enforcement agencies. In June 2006, 945 grams (2.08 lbs) of 83%-pure fentanyl powder was seized by Border Patrol agents in California from a vehicle that had entered from Mexico.[91] Mexico is the source of much of the illicit fentanyl for sale in the U.S. However, in April 2006, there was one domestic fentanyl lab discovered by law enforcement in Azusa, California. The lab was a source of counterfeit 80 mg OxyContin tablets containing fentanyl instead of oxycodone, as well as bulk fentanyl and other drugs.[92][93] In November 2016, the DEA uncovered an operation making counterfeit oxycodone and Xanax from a home in Cottonwood Heights, Utah. They found about 70,000 pills in the appearance of oxycodone and more than 25,000 in the appearance of Xanax. The DEA reported that millions of pills could have been distributed from this location over the course of time. The accused owned a pill press and ordered fentanyl in powder form from China.[94][95]

The "China White" form of fentanyl refers to any of a number of clandestinely produced analogues, especially α-methylfentanyl (AMF).[96] This Department of Justice document lists "China White" as a synonym for a number of fentanyl analogues, including 3-methylfentanyl and α-methylfentanyl,[97] which today are classified as Schedule I drugs in the United States.[96] Part of the motivation for AMF is that, despite the extra difficulty from a synthetic standpoint, the resultant drug is relatively more resistant to metabolic degradation. This results in a drug with an increased duration.[98]

In June 2013, the United States Centers for Disease Control and Prevention (CDC) issued a health advisory[99] to emergency departments alerting to 14 overdose deaths among intravenous drug users in Rhode Island associated with acetylfentanyl, a synthetic opioid analog of fentanyl that has never been licensed for medical use. In a separate study conducted by the CDC, 82% of fentanyl overdose deaths involved illegally manufactured fentanyl, while only 4% were suspected to originate from a prescription.[100]

Beginning in 2015, Canada has seen a widespread number of fentanyl overdoses. Authorities suspect that the drug is being imported from Asia to the western coast by organized crime groups in powder form and being pressed into pseudo-OxyContin tablets.[101] Traces of the drug have also been found in other recreational drugs including cocaine, MDMA, and heroin. The drug has been implicated in multiple deaths from the homeless to young professionals, including multiple teens and young parents.[102] Because of the rising deaths across the country, especially in British Columbia where the deaths for 2016 is 668 and deaths for 2017 (January to October) is 999,[103]Health Canada is putting a rush on a review of the prescription-only status of naloxone in an effort to combat overdoses of the drug.[104]

Fentanyl has been discovered for sale in illicit markets in Australia in 2017[105] and in New Zealand in 2018.[106] In response, New Zealand experts called for wider availability of naloxone.[107]

Incapacitating agent

Russian spetsnaz security forces used a fentanyl analogue or derivative to incapacitate people rapidly in the Moscow theater hostage crisis in 2002. The siege was ended, but about 130 of the 850 hostages died from the gas. The Russian Health Minister later stated that the gas was based on fentanyl,[108] but the exact chemical agent has not been identified.

Recalls of patches

In February 2004, a leading fentanyl supplier, Janssen Pharmaceutica Products, L.P., recalled one lot, and later, additional lots of fentanyl (brand name: Duragesic) patches because of seal breaches which might have allowed the medication to leak from the patch. A series of Class II recalls was initiated in March 2004, and in February 2008 ALZA Corporation recalled their 25 µg/h Duragesic patches due to a concern that small cuts in the gel reservoir could result in accidental exposure of patients or health care providers to the fentanyl gel.[109]

In February 2011, the manufacturer suspended production of all Duragesic patches due to quality control issues involving unspecified "microscopic crystallization" detected during the manufacturing process of the 100 µg/h strength.[citation needed]

Veterinary use

Fentanyl in injectable formulation is commonly used for analgesia and as a component of balanced sedation and general anaesthesia in small animal patients. Its potency and short duration of action make it particularly useful in critically ill patients. In addition, it tends to cause less vomiting and regurgitation than other pure-opioid agonists (morphine, hydromorphone) when given as a continuous post-operative infusion. As with other pure opioids, fentanyl can be associated with dysphoria in both dogs and cats.

Transdermal fentanyl has also been used for many years in dogs and cats for post-operative analgesia. This is usually done with off-label fentanyl patches manufactured for humans with chronic pain. In 2012 a highly concentrated (50 mg/ml) transdermal solution, trade name Recuvyra, has become commercially available for dogs only. It is FDA approved to provide four days of analgesia after a single application prior to surgery. It is not approved for multiple doses or other species.[110] The drug is also approved in Europe.

These fast, low-cost medical technologies will replace ultrasound and X-rays for specific uses

September 8, 2017
Original link:  http://www.kurzweilai.net/these-fast-low-cost-medical-technologies-will-replace-ultrasound-and-x-rays-for-specific-uses
Smartphone instant heart diagnosis (credit: Caltech)

A radical software invention by three Caltech engineers promises to allow your smartphone camera to provide detailed information about a critical measure of your heart’s health: the “left ventricular ejection fraction” (LVEF) — the amount of blood in the heart that is pumped out to the blood system with each beat. This figure is used by physicians as a base for diagnostic and therapeutic decisions.

You’ll simply hold your phone up to your neck for a minute or two.

In an experiment, the technique was found to be as accurate as a 45-minute echocardiography scan, which currently requires a trained technician operating an expensive ultrasound machine.

The smartphone technique measures how much the carotid artery displaces the skin of the neck as blood pumps through it. In a normal heart, the LVEF measure ranges from 50 to 70 percent. When the heart is weaker, less of the total amount of blood in the heart is pumped out with each beat, and the LVEF value is lower.

Carotid arterial waveform captured using an unmodified iPhone 5S camera by placing the iPhone camera over the carotid pulse (credit: Niema M. Pahlevan et al./Critical Card Medicine)

To test the app, clinical trials were conducted with 72 volunteers between the ages of 20 and 92 at an outpatient magnetic resonance imaging (MRI) facility. MRI is the gold standard in measuring LVEF but is seldom used clinically due to its high cost and limited availability. The measurements made by smartphone had a margin of error of ±19.1 percent compared with those done in an MRI. By way of comparison, the margin of error for echocardiography is around ±20.0 percent.

“This has the potential to revolutionize how doctors and patients can screen for and monitor heart disease, both in the U.S. and the developing world,” says Caltech’s Mory Gharib, the Hans W. Liepmann Professor of Aeronautics and Bioinspired Engineering and senior author of a paper on the study in the July issue of the Journal of Critical Care Medicine.

The researchers have founded a start-up named Avicena, LLC that has licensed this technology and will market the app. They also plan to use this approach to diagnose heart-valve diseases, like aortic stenosis and coronary artery blockage.

* For the study, the team used an iPhone 5, but they say any smartphone with a camera will work.

Seeing through the body

University of Edinburgh and Heriot-Watt University researchers have used a near-infrared camera to see through the chest to track the location of a fiber-optic endomicroscope (a long flexible tube with a light on the end) — replacing X-rays.

A “time-of-flight” camera detects light emitted from an endoscope in sheep lungs. Left: light emitted from the tip of the endoscope, revealing its precise location in the lungs. Right: an image using a conventional camera, with light scattered through the structures of the lung. (credit: Proteus)

Near-infrared light can readily pass through the body, but much of it scatters or bounces off tissues and organs rather than traveling straight through — making it nearly impossible to get a clear picture of where an object is in the body. So this camera uses a “time-of-flight” system: It calculates the distance to the endomicroscope light based on the time it takes individual photons to arrive directly (ignoring scattered photons, which take longer). That’s similar to how this camera can see an object around a corner.

The technology is so sensitive it can detect the miniscule amount of light that passes through 20 centimeters (about 8 inches) of the body’s tissue.

The research is described in an open-access paper in the journal Biomedical Optics Express.


Abstract of Noninvasive iPhone Measurement of Left Ventricular Ejection Fraction Using Intrinsic Frequency Methodology

Objective: The study is based on previously reported mathematical analysis of arterial waveform that extracts hidden oscillations in the waveform that we called intrinsic frequencies. The goal of this clinical study was to compare the accuracy of left ventricular ejection fraction derived from intrinsic frequencies noninvasively versus left ventricular ejection fraction obtained with cardiac MRI, the most accurate method for left ventricular ejection fraction measurement.

Design: After informed consent, in one visit, subjects underwent cardiac MRI examination and noninvasive capture of a carotid waveform using an iPhone camera (The waveform is captured using a custom app that constructs the waveform from skin displacement images during the cardiac cycle.). The waveform was analyzed using intrinsic frequency algorithm.

Setting: Outpatient MRI facility.

Subjects: Adults able to undergo MRI were referred by local physicians or self-referred in response to local advertisement and included patients with heart failure with reduced ejection fraction diagnosed by a cardiologist.

Interventions: Standard cardiac MRI sequences were used, with periodic breath holding for image stabilization. To minimize motion artifact, the iPhone camera was held in a cradle over the carotid artery during iPhone measurements.

Measurements and Main Results: Regardless of neck morphology, carotid waveforms were captured in all subjects, within seconds to minutes. Seventy-two patients were studied, ranging in age from 20 to 92 years old. The main endpoint of analysis was left ventricular ejection fraction; overall, the correlation between ejection fraction–iPhone and ejection fraction–MRI was 0.74 (r = 0.74; p < 0.0001; ejection fraction–MRI = 0.93 × [ejection fraction–iPhone] + 1.9).

Conclusions: Analysis of carotid waveforms using intrinsic frequency methods can be used to document left ventricular ejection fraction with accuracy comparable with that of MRI. The measurements require no training to perform or interpret, no calibration, and can be repeated at the bedside to generate almost continuous analysis of left ventricular ejection fraction without arterial cannulation.


Abstract of Ballistic and snake photon imaging for locating optical endomicroscopy fibres

We demonstrate determination of the location of the distal-end of a fibre-optic device deep in tissue through the imaging of ballistic and snake photons using a time resolved single-photon detector array. The fibre was imaged with centimetre resolution, within clinically relevant settings and models. This technique can overcome the limitations imposed by tissue scattering in optically determining the in vivo location of fibre-optic medical instruments.

Fibromyalgia

From Wikipedia, the free encyclopedia
 
Fibromyalgia
Synonyms Fibromyalgia syndrome (FMS)
Tender points fibromyalgia svg.svg
The location of the nine paired tender points that constitute the 1990 American College of Rheumatology criteria for fibromyalgia
Pronunciation
Specialty Rheumatology, neurology[2]
Symptoms Widespread pain, feeling tired, sleep problems[3][4]
Usual onset Middle age[5]
Duration Long term[3]
Causes Unknown[4][5]
Diagnostic method Based on symptoms after ruling out other potential causes[4][5]
Differential diagnosis Polymyalgia rheumatica, rheumatoid arthritis, osteoarthritis, thyroid disease[6]
Treatment Sufficient sleep and exercise, healthy diet[5]
Medication Duloxetine, milnacipran, pregabalin, gabapentin[5][7]
Prognosis Normal life expectancy[5]
Frequency 2–8%[4]

Fibromyalgia (FM) is a medical condition characterised by chronic widespread pain and a heightened pain response to pressure. Other symptoms include tiredness to a degree that normal activities are affected, sleep problems and troubles with memory. Some people also report restless legs syndrome, bowel or bladder problems, numbness and tingling and sensitivity to noise, lights or temperature. Fibromyalgia is frequently associated with depression, anxiety and posttraumatic stress disorder. Other types of chronic pain are also frequently present.

The cause of fibromyalgia is unknown; however, it is believed to involve a combination of genetic and environmental factors, with each playing a substantial role.[4][5] The condition runs in families, and many genes are believed to be involved.[8] Environmental factors may include psychological stress, trauma and certain infections.[4] The pain appears to result from processes in the central nervous system, and the condition is referred to as a "central sensitization syndrome".[3][4]

Fibromyalgia is recognized as a disorder by the US National Institutes of Health and the American College of Rheumatology.[5][9] There is no specific diagnostic test.[5] Diagnosis involves first ruling out other potential causes and verifying that a set number of symptoms are present.[4][5]

The treatment of fibromyalgia can be difficult.[5] Recommendations often include getting enough sleep, exercising regularly and eating a healthy diet.[5] Cognitive behavioral therapy (CBT) may also be helpful.[4] The medications duloxetine, milnacipran or pregabalin may be used.[5] Use of opioid pain medication is controversial, with some stating their use is poorly supported by evidence[5][10] and others saying that weak opioids may be reasonable if other medications are not effective.[11] Dietary supplements also lack evidence to support their use.[5] While fibromyalgia can last a long time, it does not result in death or tissue damage.[5]

Fibromyalgia is estimated to affect 2–8% of the population.[4] Women are affected about twice as often as men.[4] Rates appear similar in different areas of the world and among different cultures.[4] Fibromyalgia was first defined in 1990, with updated criteria in 2011.[4] There is controversy about the classification, diagnosis and treatment of fibromyalgia.[12][13] While some feel the diagnosis of fibromyalgia may negatively affect a person, other research finds it to be beneficial.[4] The term "fibromyalgia" is from New Latin fibro-, meaning "fibrous tissues", Greek μυώ myo-, "muscle", and Greek άλγος algos, "pain"; thus, the term literally means "muscle and fibrous connective tissue pain".[14]

Classification

Fibromyalgia is classed as a disorder of pain processing due to abnormalities in how pain signals are processed in the central nervous system.[15] The American College of Rheumatology classifies fibromyalgia as being a functional somatic syndrome.[12] The expert committee of the European League Against Rheumatism classifies fibromyalgia as a neurobiological disorder and as a result exclusively give pharmacotherapy their highest level of support.[12] The International Classification of Diseases (ICD-10) lists fibromyalgia as a diagnosable disease under "Diseases of the musculoskeletal system and connective tissue," under the code M79-7, and states that fibromyalgia syndrome should be classified as a functional somatic syndrome rather than a mental disorder. Although mental disorders and some physical disorders commonly are co-morbid with fibromyalgia – especially anxiety, depression, irritable bowel syndrome, and chronic fatigue syndrome – the ICD states that these should be diagnosed separately.[12]

Differences in psychological and autonomic nervous system profiles among affected individuals may indicate the existence of fibromyalgia subtypes. A 2007 review divides individuals with fibromyalgia into four groups as well as "mixed types":[16]
  1. "extreme sensitivity to pain but no associated psychiatric conditions" (may respond to medications that block the 5-HT3 receptor)
  2. "fibromyalgia and comorbid, pain-related depression" (may respond to antidepressants)
  3. "depression with concomitant fibromyalgia syndrome" (may respond to antidepressants)
  4. "fibromyalgia due to somatization" (may respond to psychotherapy)

Signs and symptoms

Fibromyalgia symptoms.svg

The defining symptoms of fibromyalgia are chronic widespread pain, fatigue, sleep disturbance, and heightened pain in response to tactile pressure (allodynia).[17] Other symptoms may include tingling of the skin (paresthesias),[17] prolonged muscle spasms, weakness in the limbs, nerve pain, muscle twitching, palpitations,[18] and functional bowel disturbances.[19][20]

Many people experience cognitive dysfunction[17][21] (known as "fibrofog"), which may be characterized by impaired concentration,[22] problems with short[22][23] and long-term memory, short-term memory consolidation,[23] impaired speed of performance,[22][23] inability to multi-task, cognitive overload,[22][23] and diminished attention span. Fibromyalgia is often associated with anxiety and depressive symptoms.[23]

Other symptoms often attributed to fibromyalgia that may be due to a comorbid disorder include myofascial pain syndrome, also referred to as chronic myofascial pain, diffuse non-dermatomal paresthesias, functional bowel disturbances and irritable bowel syndrome, genitourinary symptoms and interstitial cystitis, dermatological disorders, headaches, myoclonic twitches, and symptomatic hypoglycemia. Although fibromyalgia is classified based on the presence of chronic widespread pain, pain may also be localized in areas such as the shoulders, neck, low back, hips, or other areas. Many sufferers also experience varying degrees of myofascial pain and have high rates of comorbid temporomandibular joint dysfunction. 20–30% of people with rheumatoid arthritis and systemic lupus erythematosus may also have fibromyalgia.[24]

Cause

The cause of fibromyalgia is unknown. However, several hypotheses have been developed including "central sensitization".[17] This theory proposes that people with fibromyalgia have a lower threshold for pain because of increased reactivity of pain-sensitive nerve cells in the spinal cord or brain.[3] Neuropathic pain and major depressive disorder often co-occur with fibromyalgia – the reason for this comorbidity appears to be due to shared genetic abnormalities, which leads to impairments in monoaminergic, glutamatergic, neurotrophic, opioid and proinflammatory cytokine signaling. In these vulnerable individuals, psychological stress or illness can cause abnormalities in inflammatory and stress pathways which regulate mood and pain. Eventually, a sensitization and kindling effect occur in certain neurons leading to the establishment of fibromyalgia and sometimes a mood disorder.[25] The evidence suggests that the pain in fibromyalgia results primarily from pain processing pathways functioning abnormally. In simple terms, it can be described as the volume of the neurons being set too high and this hyper-excitability of pain processing pathways and under-activity of inhibitory pain pathways in the brain results in the affected individual experiencing pain. Some neurochemical abnormalities that occur in fibromyalgia also regulate mood, sleep, and energy, thus explaining why mood, sleep, and fatigue problems are commonly co-morbid with fibromyalgia.[15]

Genetics

A mode of inheritance is currently unknown, but it is most probably polygenic.[8] Research has also demonstrated that fibromyalgia is potentially associated with polymorphisms of genes in the serotoninergic,[26] dopaminergic[27] and catecholaminergic systems.[28] However, these polymorphisms are not specific for fibromyalgia and are associated with a variety of allied disorders (e.g. chronic fatigue syndrome,[29] irritable bowel syndrome[30]) and with depression.[31] Individuals with the 5-HT2A receptor 102T/C polymorphism have been found to be at increased risk of developing fibromyalgia.[32]

Lifestyle

Stress may be an important precipitating factor in the development of fibromyalgia.[33] Fibromyalgia is frequently comorbid with stress-related disorders such as chronic fatigue syndrome, posttraumatic stress disorder, irritable bowel syndrome and depression.[34] A systematic review found significant association between fibromyalgia and physical and sexual abuse in both childhood and adulthood, although the quality of studies was poor.[35] Poor lifestyles including being a smoker, obesity and lack of physical activity may increase the risk of an individual developing fibromyalgia.[36] A meta analysis found psychological trauma to be associated with FM, although not as strongly as in chronic fatigue syndrome.[37]

Two studies that employed single-voxel magnetic resonance spectroscopy (1H-MRS) reported metabolic abnormalities within the hippocampal complex in people with fibromyalgia. As the hippocampus plays crucial roles in maintenance of cognitive functions, sleep regulation, and pain perception, it was suggested that metabolic dysfunction of the hippocampus may be implicated in the appearance of these symptoms.[38] /[39]

Some authors have proposed that, because exposure to stressful conditions can alter the function of the hypothalamic-pituitary-adrenal (HPA) axis, the development of fibromyalgia may stem from stress-induced disruption of the HPA axis.[40]

Sleep disturbances

In 1975, Moldofsky and colleagues reported the presence of anomalous alpha wave activity (typically associated with arousal states) measured by electroencephalogram (EEG) during non-rapid eye movement sleep of "fibrositis syndrome".[20] By disrupting stage IV sleep consistently in young, healthy subjects, the researchers reproduced a significant increase in muscle tenderness similar to that experienced in "neurasthenic musculoskeletal pain syndrome" but which resolved when the subjects were able to resume their normal sleep patterns.[41]

Psychological factors

There is strong evidence that major depression is associated with fibromyalgia as with other chronic pain conditions (1999),[42] although it is unclear the direction of the causal relationship.[43] A comprehensive review into the relationship between fibromyalgia and major depressive disorder (MDD) found substantial similarities in neuroendocrine abnormalities, psychological characteristics, physical symptoms and treatments between fibromyalgia and MDD, but currently available findings do not support the assumption that MDD and fibromyalgia refer to the same underlying construct or can be seen as subsidiaries of one disease concept.[44] Indeed, the sensation of pain has at least two dimensions: a sensory dimension which processes the magnitude and location of the pain, and an affective-motivational dimension which processes the unpleasantness. Accordingly, a study that employed functional magnetic resonance imaging to evaluate brain responses to experimental pain among people with fibromyalgia found that depressive symptoms were associated with the magnitude of clinically induced pain response specifically in areas of the brain that participate in affective pain processing, but not in areas involved in sensory processing which indicates that the amplification of the sensory dimension of pain in fibromyalgia occurs independently of mood or emotional processes.[45] Fibromyalgia has also been linked with bipolar disorder, particularly the hypomania component.[46]

Non-celiac gluten sensitivity

Non-celiac gluten sensitivity (NCGS) may be an underlying cause of fibromyalgia symptoms but further research is needed.[47][48]

Pathophysiology

Pain processing abnormalities

Abnormalities in the ascending and descending pathways involved in processing pain have been observed in fibromyalgia. 50% less stimulus is needed to evoke pain in those with fibromyalgia.[49] A proposed mechanism for chronic pain is sensitization of secondary pain neurons mediated by increased release of proinflammatory cytokines and nitric oxide by glial cells.[50] Inconsistent reports of decreased serum and CSF values of serotonin have been observed. There is also some data that suggests altered dopaminergic and noradrenergic signaling in fibromyalgia.[51] Supporting the monoamine related theories is the efficacy of monoaminergic antidepressants in fibromyalgia.[52][53]

Neuroendocrine system

Studies on the neuroendocrine system and HPA axis in fibromyalgia have been inconsistent. One study found fibromyalgia patients exhibited higher plasma cortisol, more extreme peaks and troughs, and higher rates of dexamethasone non suppression. However, other studies have only found correlations between a higher Cortisol awakening response and pain, and not any other abnormalities in cortisol.[49] Increased baseline ACTH and increase in response to stress have been observed, hypothesized to be a result of decreased negative feedback.[51]

Autonomic nervous system

Autonomic nervous system abnormalities have been observed in fibromyalgia, including decreased vasoconstriction response, increased drop in blood pressure and worsening of symptoms in response to tilt table test, and decreased heart rate variability. Heart rate variabilities observed were different in males and females.[49]

Sleep

Disrupted sleep, insomnia, and poor quality sleep occur frequently in FM, and may contribute to pain by decreased release of IGF-1 and human growth hormone, leading to decreased tissue repair. Restorative sleep was correlated with improvement in pain related symptoms.[49]

Neuroimaging

Neuroimaging studies have observed decreased levels of NAA in the hippocampus of people with fibromyalgia, indicating decreased neuron functionality in this region. Altered connectivity and decreased grey matter of the default mode network,[54] the insula, and executive attention network have been found in fibromyalgia. Increased levels of glutamate and glutamine have been observed in the amygdala, parts of the prefrontal cortex, the posterior cingulate cortex, and the insula, correlating with pain levels in FM. Decreased GABA has been observed in the anterior insular in fibromyalgia. However, neuroimaging studies, in particular neurochemical imaging studies, are limited by methodology and interpretation.[55] Increased cerebral blood flow in response to pain was found in one fMRI study.[50] Findings of decreased blood flow in the thalamus and other regions of the basal ganglia correlating with treatment have been relatively consistent over three studies. Decreased binding of μ-opioid receptor have been observed; however, it is unknown if this is a result of increased endogenous binding in response to pain, or down regulation.[51]

Inflammation and immune system

Overlaps have been drawn between sickness behavior, chronic fatigue syndrome and fibromyalgia. One study found increased levels of pro-inflammatory cytokines in fibromyalgia, which may increase sensitivity to pain, and contribute to mood problems.[56] Increased levels of IL-1RA, Interleukin 6 and Interleukin 8 have been found.[57] Neurogenic inflammation has been proposed as a contributing factor to fibromyalgia.[58] A systematic review found most cytokines levels were similar in patients and controls, except for IL-1 receptor antagonist, IL-6 and IL-8[59]

Diagnosis

The location of the nine paired tender points that comprise the 1990 American College of Rheumatology criteria for fibromyalgia.

There is no single test that can fully diagnose fibromyalgia and there is debate over what should be considered essential diagnostic criteria and whether an objective diagnosis is possible. In most cases, people with fibromyalgia symptoms may also have laboratory test results that appear normal and many of their symptoms may mimic those of other rheumatic conditions such as arthritis or osteoporosis. The most widely accepted set of classification criteria for research purposes was elaborated in 1990 by the Multicenter Criteria Committee of the American College of Rheumatology. These criteria, which are known informally as "the ACR 1990", define fibromyalgia according to the presence of the following criteria:
  • A history of widespread pain lasting more than three months – affecting all four quadrants of the body, i.e., both sides, and above and below the waist.
  • Tender points – there are 18 designated possible tender points (although a person with the disorder may feel pain in other areas as well). Diagnosis is no longer based on the number of tender points.[60][61]
The ACR criteria for the classification of patients were originally established as inclusion criteria for research purposes and were not intended for clinical diagnosis but have now become the de facto diagnostic criteria in the clinical setting. The number of tender points that may be active at any one time may vary with time and circumstance. A controversial study was done by a legal team looking to prove their client's disability based primarily on tender points and their widespread presence in non-litigious communities prompted the lead author of the ACR criteria to question now the useful validity of tender points in diagnosis.[62] Use of control points has been used to cast doubt on whether a person has fibromyalgia, and to claim the person is malingering; however, no research has been done for the use of control points to diagnose fibromyalgia, and such diagnostic tests have been advised against, and people complaining of pain all over should still have fibromyalgia considered as a diagnosis.[12]

2010 provisional criteria

Widespread Pain Index (WPI) Areas

In 2010, the American College of Rheumatology approved provisional revised diagnostic criteria for fibromyalgia that eliminated the 1990 criteria's reliance on tender point testing.[63] The revised criteria use a widespread pain index (WPI) and symptom severity scale (SS) in place of tender point testing under the 1990 criteria. The WPI counts up to 19 general body areas[a] in which the person has experienced pain in the preceding two weeks. The SS rates the severity of the person's fatigue, unrefreshed waking, cognitive symptoms, and general somatic symptoms,[b] each on a scale from 0 to 3, for a composite score ranging from 0 to 12. The revised criteria for diagnosis are:
  • WPI ≥ 7 and SS ≥ 5 OR WPI 3–6 and SS ≥ 9,
  • Symptoms have been present at a similar level for at least three months, and
  • No other diagnosable disorder otherwise explains the pain.[63]:607

Multidimensional assessment

Some research has suggested not to categorise fibromyalgia as a somatic disease or a mental disorder, but to use a multidimensional approach taking into consideration somatic symptoms, psychological factors, psychosocial stressors and subjective belief regarding fibromyalgia.[64] A review has looked at self-report questionnaires assessing fibromyalgia on multiple dimensions, including:[64]

Differential diagnosis

People referred to rheumatologists may incorrectly receive a diagnosis of fibromyalgia in up to two thirds of cases.[68] Certain systemic, inflammatory, endocrine, rheumatic, infectious, and neurologic disorders may cause fibromyalgia-like symptoms, such as systemic lupus erythematosus, Sjögren syndrome, non-celiac gluten sensitivity, hypothyroidism, ankylosing spondylitis, polymyalgia rheumatica, rheumatoid arthritis, psoriatic-related polyenthesitis, hepatitis C, peripheral neuropathies, entrapment syndromes (such as carpal tunnel syndrome), multiple sclerosis and myasthenia gravis. The differential diagnosis is made during the evaluation on the basis of the person's medical history, physical examination, and laboratory investigations.[47][68][69][70]

Management

As with many other medically unexplained syndromes, there is no universally accepted treatment or cure for fibromyalgia, and treatment typically consists of symptom management. Developments in the understanding of the pathophysiology of the disorder have led to improvements in treatment, which include prescription medication, behavioral intervention, and exercise. Indeed, integrated treatment plans that incorporate medication, patient education, aerobic exercise and cognitive behavioral therapy have been shown to be effective in alleviating pain and other fibromyalgia-related symptoms.[71]

The Association of the Scientific Medical Societies in Germany,[72] the European League Against Rheumatism[73] and the Canadian Pain Society[74] currently publish guidelines for the diagnosis and management of FMS.

Medications

Health Canada and the US Food and Drug Administration (FDA) have approved pregabalin[75] and duloxetine, for the management of fibromyalgia. The FDA also approved milnacipran, but the European Medicines Agency refused marketing authority.[76]

Antidepressants

Antidepressants are "associated with improvements in pain, depression, fatigue, sleep disturbances, and health-related quality of life in people with FMS."[77] The goal of antidepressants should be symptom reduction and if used long term, their effects should be evaluated against side effects. A small number of people benefit significantly from the SNRIs duloxetine and milnacipran and the tricyclic antidepressants (TCAs), such as amitriptyline. However, many people experience more adverse effects than benefits.[78][79] While amitriptyline has been used as a first line treatment, the quality of evidence to support this use is poor.[80]

It can take up to three months to derive benefit from the antidepressant amitriptyline and between three and six months to gain the maximal response from duloxetine, milnacipran, and pregabalin. Some medications have the potential to cause withdrawal symptoms when stopping so gradual discontinuation may be warranted particularly for antidepressants and pregabalin.[12]

There is tentative evidence that the benefits and harms of SSRIs appear to be about similar.[81]

Anti-seizure medication

The anti-convulsant drugs gabapentin and pregabalin may be used to reduce pain.[82][7] There is tentative evidence that gabapentin may be of benefit for pain in about 18% of people with fibromyalgia.[7] It is not possible to predict who will benefit, and a short trial may be recommended to test the effectiveness of this type of medication. Approximately 6/10 people who take gabapentin to treat pain related to fibromyalgia experience unpleasant side effects such as dizziness, abnormal walking, or swelling from fluid accumulation.[83][needs update] Pregabalin demonstrates a benefit in about 9% of people.[84] Pregabalin reduced time off work by 0.2 days per week.[85]

Opioids

The use of opioids is controversial. As of 2015, no opioid is approved for use in this condition by the FDA.[86] The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) in 2014 stated that there was a lack of evidence for opioids for most people.[5] The Association of the Scientific Medical Societies in Germany in 2012 made no recommendation either for or against the use of weak opioids because of the limited amount of scientific research addressing their use in the treatment of FM. They strongly advise against using strong opioids.[72] The Canadian Pain Society in 2012 said that opioids, starting with a weak opioid like tramadol, can be tried but only for people with moderate to severe pain that is not well-controlled by non-opioid painkillers. They discourage the use of strong opioids and only recommend using them while they continue to provide improved pain and functioning. Healthcare providers should monitor people on opioids for ongoing effectiveness, side effects and possible unwanted drug behaviors.[74]

The European League Against Rheumatism in 2008 recommends tramadol and other weak opioids may be used for pain but not strong opioids.[73] A 2015 review found fair evidence to support tramadol use if other medications do not work.[86] A 2018 review found little evidence to support the combination of paracetamol (acetaminophen) and tramadol over a single medication.[87] Goldenberg et al suggest that tramadol works via its serotonin and norepinephrine reuptake inhibition, rather than via its action as a weak opioid receptor agonist.[10]

A large study of US people with fibromyalgia found that between 2005 and 2007 37.4% were prescribed short-acting opioids and 8.3% were prescribed long-acting opioids,[88] with around 10% of those prescribed short-acting opioids using tramadol;[89] and a 2011 Canadian study of 457 people with FM found 32% used opioids and two thirds of those used strong opioids.[74]

Others

A 2007 review concluded that a period of nine months of growth hormone was required to reduce fibromyalgia symptoms and normalize IGF-1.[90] A 2014 also found some evidence support its use.[91] Sodium oxybate increases growth hormone production levels through increased slow-wave sleep patterns. However, this medication was not approved by the FDA for the indication for use in people with fibromyalgia due to the concern for abuse.[92]

The muscle relaxants cyclobenzaprine, carisoprodol with acetaminophen and caffeine and tizanidine are sometimes used to treat fibromyalgia; however as of 2015 they are not approved for this use in the United States.[93][94] The use of NSAIDs is not recommended as first line therapy.[95] Moreover, NSAIDs cannot be considered as useful in the management of fibromyalgia.[96]

Dopamine agonists (e.g. pramipexole and ropinirole) resulted in some improvement in a minority of people,[97] but side effects, including the onset of impulse control disorders like compulsive gambling and shopping, might be a concern for some people.[98]

There is some evidence that 5HT3 antagonists may be beneficial.[99] Preliminary clinical data finds that low-dose naltrexone (LDN) may provide symptomatic improvement.[100]

Very low quality evidence suggests quetiapine may be effective in fibromyalgia.[101]

No high quality evidence exists that suggests synthetic THC (nabilone) helps with fibromyalgia.[102]

Therapy

Due to the uncertainty about the pathogenesis of FM, current treatment approaches focus on management of symptoms to improve quality of life,[103] using integrated pharmacological and non-pharmacological approaches.[104] There is no single intervention shown to be effective for all patients [105] and no gold treatment standard exists for FM.[106] Multimodal/multidisciplinary therapy is recommended to target multiple underlying factors of FM.[107] A meta-analysis of 1,119 subjects found "strong evidence that multicomponent treatment has beneficial short-term effects on key symptoms of FMS." [108]

Cognitive behavioural therapy

Non-pharmacological components include cognitive-behavioural therapy (CBT), exercise and psychoeducation (specifically, sleep hygiene).[109][110][111][112] CBT and related psychological and behavioural therapies have a small to moderate effect in reducing symptoms of fibromyalgia.[113][110] Effect sizes tend to be small when CBT is used as a stand-alone treatment for FM patients, but these improve significantly when CBT is part of a wider multidisciplinary treatment program.[114] The greatest benefit occurs when CBT is used along with exercise.[71][115]

A 2010 systematic review of 14 studies reported that CBT improves self-efficacy or coping with pain and reduces the number of physician visits at post-treatment, but has no significant effect on pain, fatigue, sleep or health-related quality of life at post-treatment or follow-up. Depressed mood was also improved but this could not be distinguished from some risks of bias.[116]

Mind-body therapy

Mind-body therapies focus on interactions among the brain, mind, body and behaviour. The National Centre for Complementary and Alternative Medicine defines the treatments under holistic principle that mind-body are interconnected and through treatment there is improvement in psychological and physical well-being, and allow patient to have an active role in their treatment.[117] There are several therapies such as mindfulness, movement therapy (yoga, tai chi), psychological (including CBT) and biofeedback (use of technology to give audio/visual feedback on physiological processes like heart rate). There is only weak evidence that psychological intervention is effective in the treatment of fibromyalgia and no good evidence for the benefit of other mind-body therapies.[117]

Exercise

There is strong evidence indicating that exercise improves fitness and sleep and may reduce pain and fatigue in some people with fibromyalgia.[118][119] In particular, there is strong evidence that cardiovascular exercise is effective for some people.[120] Studies of different forms of aerobic exercise for adults with fibromyalgia indicate that aerobic exercise improves quality of life, decreases pain, slightly improves physical function and makes no difference in fatigue and stiffness.[121] Long-term effects are uncertain.[121]

A recommended approach to a graded exercise program begins with small, frequent exercise periods and builds up from there.[122] In children, fibromyalgia is often treated with an intense physical and occupational therapy program for musculoskeletal pain syndromes. These programs also employ counseling, art therapy, and music therapy. These programs are evidence-based and report long-term total pain resolution rates as high as 88%.[123]

Prognosis

Although in itself neither degenerative nor fatal, the chronic pain of fibromyalgia is pervasive and persistent. Most people with fibromyalgia report that their symptoms do not improve over time. An evaluation of 332 consecutive new people with fibromyalgia found that disease-related factors such as pain and psychological factors such as work status, helplessness, education, and coping ability had an independent and significant relationship to FM symptom severity and function.[124]

Epidemiology

Fibromyalgia is estimated to affect 2–8% of the population.[4][125] Females are affected about twice as often as males based on criteria as of 2014.[4]

Fibromyalgia may not be diagnosed in up to 75% of affected people.[15]

History

Chronic widespread pain had already been described in the literature in the 19th century but the term fibromyalgia was not used until 1976 when Dr P.K. Hench used it to describe these symptoms.[12] Many names, including "muscular rheumatism", "fibrositis", "psychogenic rheumatism", and "neurasthenia" were applied historically to symptoms resembling those of fibromyalgia.[126] The term fibromyalgia was coined by researcher Mohammed Yunus as a synonym for fibrositis and was first used in a scientific publication in 1981.[127] Fibromyalgia is from the Latin fibra (fiber)[128] and the Greek words myo (muscle)[129] and algos (pain).[130]

Historical perspectives on the development of the fibromyalgia concept note the "central importance" of a 1977 paper by Smythe and Moldofsky on fibrositis.[131][132] The first clinical, controlled study of the characteristics of fibromyalgia syndrome was published in 1981,[133] providing support for symptom associations. In 1984, an interconnection between fibromyalgia syndrome and other similar conditions was proposed,[134] and in 1986, trials of the first proposed medications for fibromyalgia were published.[134]

A 1987 article in the Journal of the American Medical Association used the term "fibromyalgia syndrome" while saying it was a "controversial condition".[135] The American College of Rheumatology (ACR) published its first classification criteria for fibromyalgia in 1990,[136] although these are not strictly diagnostic criteria.[16]

Society and culture

Economics

People with fibromyalgia generally have higher health-care costs and utilization rates. A study of almost 20,000 Humana members enrolled in Medicare Advantage and commercial plans compared costs and medical utilizations and found that people with fibromyalgia used twice as much pain-related medication as those without fibromyalgia. Furthermore, the use of medications and medical necessities increased markedly across many measures once diagnosis was made.[137]

Controversies

Fibromyalgia was defined relatively recently. It continues to be a disputed diagnosis. Dr. Frederick Wolfe, lead author of the 1990 paper that first defined the diagnostic guidelines for fibromyalgia, stated in 2008, that he believed it "clearly" not to be a disease but instead a physical response to depression and stress,.[138] In 2013 Wolfe added that its causes "are controversial in a sense" and "there are many factors that produce these symptoms – some are psychological and some are physical and it does exist on a continuum".[139]

Some members of the medical community do not consider fibromyalgia a disease because of a lack of abnormalities on physical examination and the absence of objective diagnostic tests.[131][140]

Neurologists and pain specialists tend to view fibromyalgia as a pathology due to dysfunction of muscles and connective tissue as well as functional abnormalities in the central nervous system. Rheumatologists define the syndrome in the context of "central sensitization" – heightened brain response to normal stimuli in the absence of disorders of the muscles, joints, or connective tissues. On the other hand, psychiatrists often view fibromyalgia as a type of affective disorder, whereas specialists in psychosomatic medicine tend to view fibromyalgia as being a somatic symptom disorder. These controversies do not engage healthcare specialists alone; some patients object to fibromyalgia being described in purely somatic terms. There is extensive research evidence to support the view that the central symptom of fibromyalgia, namely pain, has a neurogenic origin, though this is consistent in both views.[12][15]

The validity of fibromyalgia as a unique clinical entity is a matter of contention because "no discrete boundary separates syndromes such as FMS, chronic fatigue syndrome, irritable bowel syndrome, or chronic muscular headaches".[120][141] Because of this symptomatic overlap, some researchers have proposed that fibromyalgia and other analogous syndromes be classified together as functional somatic syndromes for some purposes.[142]

Research

Investigational medications include cannabinoids and the 5-HT3 receptor antagonist tropisetron.[143] Low quality evidence found an improvement in symptoms with a gluten free diet among those without celiac disease.[144] A controlled study of guaifenesin failed to demonstrate any benefits from this treatment.

Significant other

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