Phenibut , sold under the trademark of Anvifen , Fenibut , and Noofen among others, are central nervous system depressants with anxiolytic effects and sedatives used in Russia, Ukraine, Kazakhstan and Latvia for the treatment of anxiety, insomnia, and various other indications. It is not approved for clinical use in the United States and most of Europe, but is sold through the Internet as a supplement and is recognized nootropic.
Phenibut structurally related to neurotransmitter? -aminobutyric acid (GABA), and therefore is a GABA analogue. It is thought to act as a GABA receptor agonist B , just like baclofen and? -hydroxybutyrate (GHB). Further research found that it is also a blocker? 2 ? subunits containing calcium-dependent channels of stress (VDCCs), just like gabapentinoids such as gabapentin and pregabalin.
Video Phenibut
Medical use
Phenibut is used in Russia, Ukraine, and Latvia as a pharmaceutical drug to treat anxiety and to improve sleep (for example, in the treatment of insomnia). It is also used for a variety of other indications, including asthenia treatment, depression, alcoholism, alcohol withdrawal syndrome, post-traumatic stress disorder, stuttering, tics, vestibular disorders, MÃÆ' Â © niÃÆ'¨re, dizziness, for movement prevention. disease, and for the prevention of anxiety before or after surgical procedures or painful diagnostic tests.
Available form
Phenibut is available as a drug in the form of 250 mg tablet for oral administration and as a solution at 10 mg/mL concentration for infusion.
Maps Phenibut
Contraindications
Contraindications to fenibut include:
- Intolerance to phenibut
- Pregnancy and breastfeeding
- Children younger than two years
- Insufficiency or liver failure
- Ulcerative lesions of the gastrointestinal tract
Phenbut should not be combined with alcohol.
Side effects
Phenibut is generally well tolerated. Possible side effects may include sedation, somnolence, nausea, irritability, agitation, anxiety, dizziness, headache, and allergic reactions such as skin rashes and itching. At high doses, motor incoordination, loss of balance, and hangover may occur. Tolerance develops into a fenibut with repeated use. Withdrawal symptoms may occur after discontinuation, and, in high-dose recreational users, have been reported including severe rebound anxiety, insomnia, anger, irritability, agitation, visual and auditory hallucinations, and acute psychosis. Because of the central nervous system's depressant effects, people taking phen- gut should refrain from potentially dangerous activities such as operating heavy machinery. With prolonged use of fenibut, especially at high doses, the liver and blood should be monitored, due to the risk of fatty liver disease and eosinophilia.
Overdose
In overdose, phenibut can cause severe drowsiness, nausea, vomiting, eosinophilia, decreased blood pressure, kidney disorders, and, above 7 grams, fatty liver degeneration. There is no specific antidote for phenotypic overdose. Fatigue, somnolence, agitation, delirium, tonic-clonic seizures, reduced consciousness or unconsciousness, and unresponsiveness have been reported to overdose recreational users. Management of overdose fenibut includes active charcoal, gastric lavage, induced vomiting, and symptom-based treatments. Unlike some other central nervous system depressants such as baclofen and GHB, there have been no death reports associated with phenogenic overdose.
Interactions
Phenibut may mutually potentiate and prolong the duration of central nervous system depressant effects including anxiolytics, antipsychotics, sedatives, opioids, anticonvulsants, and alcohols.
Pharmacology
Pharmacodynamics
Phenibut acts as a full receptor agonist GABA B , just like baclofen. It has between 30 to 68 times lower affinity for GABA receptors B than baclofen, which, accordingly, is used at much lower doses than. ( R ) - Phenibut has more than 100 times higher affinity for GABA receptors B than ( S ) - phenibut; hence, ( R ) - phenibut is the active enantiomer of GABA receptor B . At very high concentrations, phenotypes are reported to also act as GABA receptor agonists A , which are the receptors responsible for the action of benzodiazepines, barbiturates, and alcohols.
Phenibut also bind and block? 2 ? VDCC containing subunits, just like gabapentin and pregabalin, and hence gabapentinoid. Both ( R ) - phenibut and ( S ) - phenibut display this action with the same affinity (K i = 23 and 39Ã,? M , each ). In addition, ( R ) - phenibut has a 4-fold greater affinity for this site than GABA receptors B (K i = 92Ã, ? M), while ( S ) - phenibut does not bind significantly to GABA receptors B (K i & gt; 1 mM). Thus, based on the results of this study, phenibut seems to have a much greater potential in its interaction with? 2 ? VDCC containing subunits compared with GABA recipes B (between 5 and 10 fold). For this reason, phenibut action as? 2 ? a subunit containing a voltage-gated or gabapentinoid channel calcium channel may be the ultimate correct mechanism of action, and this may explain the difference between the relatively close phenibut and baclofen (which, on the other hand, has an essentially insignificant activity as gabapentinoid; K i = 6a, M for GABA receptors B and K i = 156Ã,? M for? 2 ? Subunit-containing VDCC, or difference 26-fold in affinity).
( R ) - phenibut and ( S ) - phenibut were tested at 85 binding sites at 100 Ã, μM concentration with no activity (less than 20% inhibition of binding) observed except on ? 2 ? VDCC subunit and GABA receptor B . In this study, ( R ) - phenibut and ( S ) - phenibut showed IC value 50 for inhibition of gabapentin binding of 87.1 ÂμM and 91.0Ã,ÂμM (K i = 60 ÂμM), respectively. IC 50 for gabapentin with the same condition is 0.09 ÂμM. The researchers also assessed the phenotype of the GABA receptor B and found a value of K i of 57Ã,ÂμM for ( R ) - phenibut, which would be about twice that concentration (~ 114 μμM) with racemic phenibut.
Pharmacokinetics
Very little information has been published on clinical pharmacokinetics of phenibut. The drug is reportedly well absorbed. It distributes widely throughout the body and crosses the blood-brain barrier. About 0.1% of the dose given phenibut is reported to penetrate to the brain, thus it is said to occur at a much greater rate in young people and the elderly. After a single dose of 250 mg in healthy volunteers, the elimination half-life was about 5.3 hours and most drugs (63%) excreted in the urine did not change. In animals, the absolute bioavailability of phenbut is 64% after oral and intravenous administration, apparently to undergo minimal or no metabolism in some species, and it crosses the blood-brain barrier to levels significantly greater than GABA. Phenotubic metabolites are reported to be inactive.
Some limited information has been described in pharmacoketetic phenotypes in recreational users who take much higher doses (eg, 1-3 grams) than typical clinical doses. In this individual, the onset of action of the fenibut has been reported 2 to 4 hours orally and 20 to 30 minutes rectally, peak effects are described occurring 4 to 6 hours after oral consumption, and the total duration for the oral route. has been reported 15 to 24 hours (or about 3 to 5 terminals).
Chemistry
Phenbut is a synthetic aromatic amino acid. It is a chiral molecule and thus has two potential configurations, such as ( R ) - and ( S ) - enantiomer.
Structure and analog
Phenibut is a derivative of GABA neurotransmitter inhibition. Therefore, this is a GABA analogue. Phenibut is typically a GABA analog with a replaced phenyl ring in-position. Thus, the chemical name is? -phenyl -? - aminobutyric acid, which can be abbreviated as? -phenyl-GABA. The presence of a phenyl ring allows the phenbut to cross the blood-brain barrier significantly, unlike the case of GABA. Phenibut also contains traces of amines? phenethylamine in its structure.
Phenibut is closely related to other GABA analogues including baclofen (? - (4-chlorophenyl) -GABA), 4-fluorophenibut (?-(-of-fluorophenyl) -GABA), tolibut (? - (4-methylphenyl) - GABA) , pregabalin (( S ) -? - isobutyl-GABA), gabapentin (1- (aminomethyl) cyclohexane acetyl acid), and GABOB (? -hydroxy-GABA). It has a chemical structure similar to that of baclofen, different from having only a hydrogen atom instead of a chlorine atom at the position of the phenyl ring. Phenibut is also close to the pregabalin structure, which has isobutyl groups in? position not phenyl ring phenibut.
Synthesis
Chemical synthesis of phenut has been published.
History
Phenibut was synthesized at A. I. Herzen Leningrad Pedagogical Institute (USSR) by the team of Professor Vsevolod Perekalin and tested at the Institute of Experimental Medicine, USSR Academy of Medical Sciences. It was introduced to clinical use in Russia in the 1960s.
Society and culture
Common names
The generic name of phenibut is fenibut , phenibut , or phenybut (Russian: ???????). Sometimes also referred to as aminophenylbutyric acid (Russian: ?????????????????????). The word phenibut is a contraction of the chemical name of the drug, ? - pheny l -? - amino but yric acid . In the initial publication, phenibut is referred to as fenigam and phenigama (and its spelling variant; Russia: ??????? and ????????). Drug has not been given INN .
Brand name
Phenibut is marketed in Russia, Ukraine and Latvia under the brand name Anvifen, Fenibut, and Noofen (Russia: ????????????????????????????? ??????????????????????????????????????????????????
Availability
Phenibut approved in Russia, Ukraine, and Latvia for medical purposes. It is not approved or available as medicine in other countries in the European Union, the United States, or Australia. In countries where phenibut is not a licensed pharmaceutical drug, it is sold online without a prescription as a "nutritional supplement". It is often used as a form of self-medication for social anxiety.
Use of recreation
Phenibut is used recreatively for its ability to produce euphoria, anxiolysis, and social skills improvement. Due to its delayed effect, users first often mistakenly take an additional dose of phenibut in the belief that the initial dose is not working. Recreational users usually take oral medication; there were several cases of rectal administration and an insufflation report, described as "very painful" and causing a swollen nostril.
Legal status
In 2018, phenibut is not a controlled substance in any country other than Australia. By 2015, it is recommended that the legal status of phenobi in Europe should be reconsidered because of its potential for recreation. In February 2018, the Australian Therapeutic Goods Administration stated it was a banned substance (schedule 9), citing health problems due to withdrawal and overdose.
References
External links
- 4-Amino-3-phenylbutyric acid in ChemIDplus database
Source of the article : Wikipedia
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