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词条 Piracetam
释义

  1. Medical uses

     Dementia  Depression and anxiety  Other 

  2. Side effects

     Toxicity 

  3. Mechanisms of action

  4. History

  5. Approval

  6. Availability

  7. See also

  8. Notes

  9. References

  10. External links

{{Drugbox
| Watchedfields = changed
| verifiedrevid = 464207742
| IUPAC_name = 2-(2-Oxopyrrolidin-1-yl)acetamide
| image = Piracetam.svg
| image2 = Piracetam ball-and-stick.png
| alt =
| caption =
| tradename = Breinox, Dinagen, Lucetam, Nootropil, Nootropyl, Oikamid, Piracetam and many others
| Drugs.com = {{Drugs.com|international|piracetam}}
| legal_AU = Schedule 4
| legal_CA = Unscheduled
| legal_UK = POM
| legal_US_comment = Not permitted as drug or supplement
| routes_of_administration = By mouth, parenteral, or vaporized
| bioavailability = ~100%
| protein_bound =
| metabolism =
| elimination_half-life = 4–5 hr
| excretion = Urinary
| CAS_number_Ref = {{cascite|correct|CAS}}
| CAS_number = 7491-74-9
| ATC_prefix = N06
| ATC_suffix = BX03
| PubChem = 4843
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 4677
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = ZH516LNZ10
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D01914
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 36715
| IUPHAR_ligand = 4288
| C=6 | H=10 | N=2 | O=2
| molecular_weight = 142.16 g/mol
| smiles = O=C1N(CC(=O)N)CCC1
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C6H10N2O2/c7-5(9)4-8-3-1-2-6(8)10/h1-4H2,(H2,7,9)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = GMZVRMREEHBGGF-UHFFFAOYSA-N
|drug_name=|type=|MedlinePlus=|legal_status=|licence_EU=|pregnancy_AU=|pregnancy_US=|pregnancy_category=|licence_US=|DrugBank=|melting_point=152.0}}Piracetam (sold under many brand names) is a medication in the racetams group, with chemical name 2-oxo-1-pyrrolidine acetamide. It is approved in the United Kingdom[1] but is not approved in the United States.[2][3] In the UK, piracetam is prescribed mainly for myoclonus,[4] but is used off-label for other conditions. Evidence to support its use for many conditions is unclear, although it is marketed as a nootropic (cognitive enhancer). Studies of piracetam's cognitive effects have had equivocal results, sometimes showing modest benefits in specific populations and sometimes showing minimal or no benefit.[5]

It shares the same 2-oxo-pyrrolidone base structure with pyroglutamic acid. Piracetam is a cyclic derivative of GABA (gamma-Aminobutyric acid). Related drugs include the anticonvulsants levetiracetam and brivaracetam, and the putative nootropics aniracetam and phenylpiracetam.

Medical uses

Dementia

A 2001 Cochrane review concluded that there was not enough evidence to support piracetam for dementia or cognitive problems.[6] A 2002 review and 2005 review concluded that piracetam had some positive effects in older patients with these problems.[7][8] In 2008, a working group of the British Academy of Medical Sciences noted that many of the trials of piracetam for dementia were flawed.[9][10]

Depression and anxiety

Some sources suggest that piracetam's overall effect on lowering depression and anxiety is higher than on improving memory.[11] However, depression is reported to be an occasional adverse effect of piracetam.[12]

Other

Peripheral vascular effects of piracetam have suggested its use potential for vertigo, dyslexia and sickle cell anemia.[8] There is no evidence to support piracetam's use in sickle cell crisis prevention[13] or for fetal distress during childbirth.[14] There is no evidence for benefit of piracetam with acute ischemic stroke,[15] though there is debate as to its utility during stroke rehabilitation.[16][17]

Side effects

Piracetam has been found to have very few side effects, and those it has are typically "few, mild, and transient."[18] A large-scale, 12-week trial of high-dose piracetam found no adverse effects occurred in the group taking piracetam as compared to the placebo group.[19] Many other studies have likewise found piracetam to be well tolerated.[18][20][21]

Symptoms of general excitability, including anxiety, insomnia, irritability, headache, agitation, nervousness, tremor, and hyperkinesia, are occasionally reported.[12][22][23] Other reported side effects include somnolence, weight gain, clinical depression, weakness, increased libido, and hypersexuality.[12]

Toxicity

Piracetam does not appear to be acutely toxic at the doses used in human studies.[6][18][20] The {{LD50}} for oral consumption in humans has not been determined.[31] The LD50 is 5.6 g/kg for rats and 20 g/kg for mice, indicating extremely low acute toxicity.[24] For comparison, in rats the LD50 of Vitamin C is 12g/kg and the LD50 of table salt is 3g/kg.

Mechanisms of action

Piracetam's mechanism of action, as with racetams in general, is not fully understood. The drug influences neuronal and vascular functions and influences cognitive function without acting as a sedative or stimulant.[8] Piracetam is a positive allosteric modulator of the AMPA receptor, although this action is very weak and its clinical effects may not necessarily be mediated by this action.[25] It is hypothesized to act on ion channels or ion carriers, thus leading to increased neuron excitability.[26] GABA brain metabolism and GABA receptors are not affected by piracetam [27]

It has been found to increase blood flow and oxygen consumption in parts of the brain, but this may be a side effect of increased brain activity rather than a primary effect or mechanism of action for the drug.[28]

Piracetam improves the function of the neurotransmitter acetylcholine via muscarinic cholinergic (ACh) receptors{{citation needed|date=August 2017}}, which are implicated in memory processes.[29] Furthermore, piracetam may have an effect on NMDA glutamate receptors, which are involved with learning and memory processes. Piracetam is thought to increase cell membrane permeability.[29][30] Piracetam may exert its global effect on brain neurotransmission via modulation of ion channels (i.e., Na+, K+).[26] It has been found to increase oxygen consumption in the brain, apparently in connection to ATP metabolism, and increases the activity of adenylate kinase in rat brains.[31][32] Piracetam, while in the brain, appears to increase the synthesis of cytochrome b5,[33] which is a part of the electron transport mechanism in mitochondria. But in the brain, it also increases the permeability of some intermediates of the Krebs cycle through the mitochondrial outer membrane.[31]

History

Piracetam was first made some time between the 1950s and 1964 by Corneliu E. Giurgea.[34] There are reports of it being used for epilepsy in the 1950s.[35]

Approval

Piracetam is primarily used in Europe, Asia, and South America.{{citation needed|date=October 2017}} In the United States, it is not approved by the US Food and Drug Administration for any medical use and it is not permitted to be sold as a dietary supplement. Piracetam is legal to import into the United Kingdom for personal use with or without prescription.{{citation needed|date=April 2015}} Piracetam has no DIN in Canada, and thus cannot be sold but can be imported for personal use in Canada.[36] It has become popular as a cognitive enhancement drug among students.[37]

Availability

Piracetam is sold under a wide variety of brand names worldwide. Popular trade names for piracetam in Europe are Nootropil and Lucetam, among many others. In Argentina, it is made by GlaxoSmithKline S.A. laboratories and sold under the trade name of Noostan (800 mg or 1200 mg). In Venezuela and Ecuador, piracetam is produced by Laboratorios Farma S.A. and sold under the brand name Breinox. In Mexico it is produced by UCB de Mexico, and sold under the brand name of Nootropil. Other names include Nootropil in the United States, Europe, Brazil, Hong Kong, India, and Mexico; Lucetam, Oikamid, Smart, Geratam, and Biotropil in Europe and Brazil; Neurobasal in Colombia; Breinox in Ecuador and Venezuela; Cerecetam in India; Stimulan in Egypt; and Nocetan in Latin America.

See also

  • AMPA receptor positive allosteric modulator
  • Aniracetam
  • Brivaracetam — an analogue of piracetam with the same additional side chain as levetiracetam and a three–carbon chain. It exhibits greater antiepileptic properties than levetiracetam in animal models, but with a somewhat smaller, although still high, therapeutic range.
  • Hydergine
  • Levetiracetam — an analogue of piracetam bearing an additional CH3–CH2– sidechain and bearing antiepileptic pharmacological properties through a poorly understood mechanism probably related to its affinity for the vesicle protein SV2A.
  • Oxiracetam
  • Phenylpiracetam — a phenylated analog of the drug piracetam which was developed in 1983 in Russia where it is available as a prescription drug.
  • Pramiracetam

Notes

1. ^{{Cite web|url=https://pubchem.ncbi.nlm.nih.gov/compound/piracetam#section=Drug-Warning|title=Piracetam|last=Pubchem|website=pubchem.ncbi.nlm.nih.gov|language=en|access-date=2018-11-20}}
2. ^Inspections, Compliance, Enforcement, and Criminal Investigations
3. ^Enforcement Report - Week of 20 March 2013
4. ^{{cite web |url=http://www.netdoctor.co.uk/medicines/100001864.html |title=Nootropil |publisher=NetDoctor.co.uk |date=8 July 2004 |accessdate=21 September 2009}}
5. ^{{Cite journal|last=Winblad|first=Bengt|date=2005|title=Piracetam: a review of pharmacological properties and clinical uses|journal=CNS Drug Reviews|volume=11|issue=2|pages=169–182|issn=1080-563X|pmid=16007238|doi=10.1111/j.1527-3458.2005.tb00268.x}}
6. ^1 {{cite journal|last1=Flicker|first1=L|last2=Grimley Evans|first2=J|authorlink2=John Grimley Evans|title=Piracetam for dementia or cognitive impairment.|journal=The Cochrane Database of Systematic Reviews|date=2001|issue=2|pages=CD001011|pmid=11405971|doi=10.1002/14651858.CD001011}}
7. ^{{cite journal|last1=Waegemans|first1=T|last2=Wilsher|first2=CR|last3=Danniau|first3=A|last4=Ferris|first4=SH|last5=Kurz|first5=A|last6=Winblad|first6=B|title=Clinical efficacy of piracetam in cognitive impairment: a meta-analysis.|journal=Dementia and Geriatric Cognitive Disorders|date=2002|volume=13|issue=4|pages=217–24|pmid=12006732|doi=10.1159/000057700}}
8. ^1 2 {{Cite journal |doi=10.1111/j.1527-3458.2005.tb00268.x |pmid=16007238 |year=2005 |last1=Winblad |first1=B |title=Piracetam: a review of pharmacological properties and clinical uses |volume=11 |issue=2 |pages=169–82 |journal=CNS Drug Reviews}}
9. ^{{cite report |url=http://www.acmedsci.ac.uk/download.php?file=/images/publication/Report.pdf |publisher=Academy of Medical Sciences |vauthors=Horne G, etal |title=Brain science, addiction and drugs |date=May 2008 |isbn=1-903401-18-6 |page=145 }}
10. ^{{Cite journal|first=Margaret |last=Talbot |date=27 April 2009 |url=http://www.newyorker.com/reporting/2009/04/27/090427fa_fact_talbot |title=Brain Gain: The underground world of 'neuroenhancing' drugs |journal=The New Yorker |accessdate=21 September 2009}}
11. ^{{cite journal |vauthors=Malykh AG, Sadaie MR | title = Piracetam and piracetam-like drugs: from basic science to novel clinical applications to CNS disorders | journal = Drugs | volume = 70 | issue = 3 | pages = 287–312 |date=February 2010 | pmid = 20166767 | doi = 10.2165/11319230-000000000-00000 }}
12. ^1 2 Nootropil®. Arzneimittel-Kompendium der Schweiz. 2013-09-12. Retrieved 2013-10-27.
13. ^{{Cite journal|last=Al Hajeri|first=Amani|last2=Fedorowicz|first2=Zbys|date=2016-02-12|title=Piracetam for reducing the incidence of painful sickle cell disease crises|journal=The Cochrane Database of Systematic Reviews|volume=2|pages=CD006111|doi=10.1002/14651858.CD006111.pub3|issn=1469-493X|pmid=26869149}}
14. ^{{cite journal |last1=Hofmeyr |first1=GJ |last2=Kulier |first2=R |title=Piracetam for fetal distress in labour. |journal=The Cochrane Database of Systematic Reviews |date=2002 |issue=1 |pages=CD001064 |doi=10.1002/14651858.CD001064 |pmid=11869588}}
15. ^{{cite journal |last1=Ricci |first1=S |last2=Celani |first2=MG |last3=Cantisani |first3=TA |last4=Righetti |first4=E |title=Piracetam for acute ischaemic stroke. |journal=The Cochrane Database of Systematic Reviews |date=12 September 2012 |issue=9 |pages=CD000419 |doi=10.1002/14651858.CD000419.pub3 |pmid=22972044}}
16. ^{{cite journal |last1=Zhang |first1=J |last2=Wei |first2=R |last3=Chen |first3=Z |last4=Luo |first4=B |title=Piracetam for Aphasia in Post-stroke Patients: A Systematic Review and Meta-analysis of Randomized Controlled Trials. |journal=CNS Drugs |date=July 2016 |volume=30 |issue=7 |pages=575–87 |doi=10.1007/s40263-016-0348-1 |pmid=27236454}}
17. ^{{cite journal |last1=Yeo |first1=SH |last2=Lim |first2=ZI |last3=Mao |first3=J |last4=Yau |first4=WP |title=Effects of Central Nervous System Drugs on Recovery After Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. |journal=Clinical Drug Investigation |date=October 2017 |volume=37 |issue=10 |pages=901–928 |doi=10.1007/s40261-017-0558-4 |pmid=28756557}}
18. ^1 2 {{Cite journal|pmid=9527146 |doi=10.1136/jnnp.64.3.344 |pmc=2169975 |year=1998 |last1=Koskiniemi |first1=M |last2=Van Vleymen |last3=Hakamies |last4=Lamusuo |last5=Taalas |title=Piracetam relieves symptoms in progressive myoclonus epilepsy: a multicentre, randomised, double blind, crossover study comparing the efficacy and safety of three dosages of oral piracetam with placebo |volume=64 |issue=3 |pages=344–8 |journal=Journal of Neurology, Neurosurgery, and Psychiatry |first2=B |first3=L |first4=S |first5=J}}
19. ^{{Cite journal|pmid=10338106 |year=1999 |last1=De Reuck |first1=J |last2=Van Vleymen |title=The clinical safety of high-dose piracetam--its use in the treatment of acute stroke |volume=32 Suppl 1 |pages=33–7 |journal=Pharmacopsychiatry |first2=B |doi=10.1055/s-2007-979234}}
20. ^1 {{Cite journal|pmid=11346373 |year=2001 |last1=Fedi |first1=M |last2=Reutens |last3=Dubeau |last4=Andermann |last5=D'agostino |last6=Andermann |title=Long-term efficacy and safety of piracetam in the treatment of progressive myoclonus epilepsy |volume=58 |issue=5 |pages=781–6 |journal=Archives of Neurology |doi=10.1001/archneur.58.5.781 |first2=D |first3=F |first4=E |first5=D |first6=F}}
21. ^{{Cite journal|last1=Giurgea |first1=C. |last2=Salama |first2=M. |title=Nootropic drugs |journal=Prog Neuropsychopharmacol |volume=1 |year=1977 |pages=235–247 |doi=10.1016/0364-7722(77)90046-7|issue=3–4}}
22. ^{{Cite journal|pmid=6415738 |doi=10.1007/BF00429000 |year=1983 |last1=Chouinard |first1=G |last2=Annable |last3=Ross-Chouinard |last4=Olivier |last5=Fontaine |title=Piracetam in elderly psychiatric patients with mild diffuse cerebral impairment |volume=81 |issue=2 |pages=100–6 |journal=Psychopharmacology |first2=L |first3=A |first4=M |first5=F}}
23. ^{{Cite journal|pmid=342247 |doi=10.1159/000114922 |year=1978 |last1=Hakkarainen |first1=H |last2=Hakamies |title=Piracetam in the treatment of post-concussional syndrome. A double-blind study |volume=17 |issue=1 |pages=50–5 |journal=European Neurology |first2=L}}
24. ^{{cite web|title=Piracetam Material Safety Sheet|url=https://www.spectrumchemical.com/MSDS/P3941.PDF|publisher=Spectrum}}
25. ^{{Cite journal| doi=10.1021/jm901905j| year=2010 |last1=Ahmed |first1=A |last2=Oswald| first2=R |title=Piracetam Defines a New Binding Site for Allosteric Modulators of α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors |journal=Journal of Medicinal Chemistry |volume=53| issue=5 | pages=2197–2203| pmid=20163115| pmc=2872987}}
26. ^1 2 {{Cite journal|pmid=8061686 |year=1994 |last1=Gouliaev |first1=AH |last2=Senning |title=Piracetam and other structurally related nootropics |volume=19 |issue=2 |pages=180–222 |journal=Brain Research. Brain Research Reviews |doi=10.1016/0165-0173(94)90011-6 |first2=A}}
27. ^{{Cite journal|title = The nootropic concept and its prospective implications|journal = Drug Development Research|date = 1982-01-01|issn = 1098-2299|pages = 441–446|volume = 2|issue = 5|doi = 10.1002/ddr.430020505|first = Corneliu E.|last = Giurgea}}
28. ^{{Cite journal|pmid=8876930 |year=1996 |last1=Jordaan |first1=B |last2=Oliver |last3=Dormehl |last4=Hugo |title=Cerebral blood flow effects of piracetam, pentifylline, and nicotinic acid in the baboon model compared with the known effect of acetazolamide |volume=46 |issue=9 |pages=844–7 |journal=Arzneimittel-Forschung |first2=DW |first3=IC |first4=N}}
29. ^1 {{Cite journal|pmid=16459490 |year=2005 |last1=Winnicka |first1=K |last2=Tomasiak |last3=Bielawska |title=Piracetam--an old drug with novel properties? |volume=62 |issue=5 |pages=405–9 |journal=Acta Poloniae Pharmaceutica |first2=M |first3=A}}
30. ^{{Cite journal|pmid=10338102 |year=1999 |last1=Müller |first1=WE |last2=Eckert |last3=Eckert |title=Piracetam: novelty in a unique mode of action |volume=32 Suppl 1 |pages=2–9 |journal=Pharmacopsychiatry |doi=10.1055/s-2007-979230 |first2=GP |first3=A}}
31. ^1 {{Cite journal|pmid=3569848 |year=1987 |last1=Grau |first1=M |last2=Montero |last3=Balasch |title=Effect of Piracetam on electrocorticogram and local cerebral glucose utilization in the rat |volume=18 |issue=2 |pages=205–11 |journal=General Pharmacology |first2=JL |first3=J |doi=10.1016/0306-3623(87)90252-7}}
32. ^{{Cite journal|pmid=985556 |year=1976 |last1=Nickolson |first1=VJ |last2=Wolthuis |title=Effect of the acquisition-enhancing drug piracetam on rat cerebral energy metabolism. Comparison with naftidrofuryl and methamphetamine |volume=25 |issue=20 |pages=2241–4 |journal=Biochemical pharmacology |doi=10.1016/0006-2952(76)90004-6 |first2=OL}}
33. ^{{Cite journal|pmid=3946121 |year=1986 |last1=Tacconi |first1=MT |last2=Wurtman |title=Piracetam: physiological disposition and mechanism of action |volume=43 |pages=675–85 |journal=Advances in Neurology |first2=RJ}}
34. ^{{cite book|last1=Li|first1=Jie Jack|last2=Corey|first2=E. J.|title=Drug Discovery: Practices, Processes, and Perspectives|date=2013|publisher=John Wiley & Sons|isbn=9781118354469|page=276|url=https://books.google.ca/books?id=mIyxO5cLEAcC&pg=PA276|language=en}}
35. ^{{cite book|last1=M.D|first1=Emeritus Profess of Neurology and Head of Epilepsy Research Group Berlin Dieter Schmidt|last2=Shorvon|first2=Emeritus Profess of Neurology and Consultant Neurologist Simon|title=The End of Epilepsy?: A History of the Modern Era of Epilepsy Research 1860-2010|date=2016|publisher=Oxford University Press|isbn=9780198725909|page=69|url=https://books.google.ca/books?id=upjSDAAAQBAJ&pg=PA68|language=en}}
36. ^{{Cite web|url=http://www.hc-sc.gc.ca/dhp-mps/compli-conform/import-export/gui-0084_biu-uif-eng.php#a6|title=Guidance Document on the Import Requirements for Health Products under the Food and Drugs Act and its Regulations (GUI-0084) [Health Canada, 2010]|last=#2|first=Government of Canada, Health Canada, Health Products and Food Branch, HPFB Inspectorate, Inspectorate Ottawa, Compliance, Enforcement and Coordination Division|website=www.hc-sc.gc.ca|access-date=2016-03-06|date=June 2010}}
37. ^{{cite web|last=Medew|first=Julia|title=Call for testing on 'smart drugs'|url=http://www.watoday.com.au/national/call-for-testing-on-smart-drugs-20091002-gf8t.html|publisher=Fairfax Media|accessdate=29 May 2014|date=1 October 2009}}

References

  • {{Cite web| author=UCB Pharma Limited | year=2005 | url=http://emc.medicines.org.uk/emc/assets/c/html/displaydoc.asp?documentid=16509 | title=Nootropil 800 mg & 1200 mg Tablets and Solution | work=electronic Medicines Compendium | publisher=Datapharm Communications | accessdate=8 December 2005}}

External links

{{Commons category|Piracetam}}
  • {{cite web |url= http://www.ceri.com/noot.htm |title= Piracetam (Nootropyl) |first1= Ward |last1= Dean |first2= John |last2= Morgenthaler |publisher= Cognitive Enhancement Research Institute (CERI) |work= Excerpts: Smart Drugs & Nutrients |date= 1990 }}
  • {{cite journal |pmid= 8061686 |journal= Brain Research Reviews|date= May 1994 |volume= 19 |issue= 2 |pages=180–222 |title= Piracetam and other structurally related nootropics |last1= Gouliaev |first1= AH |last2= Senning |first2= A |doi=10.1016/0165-0173(94)90011-6}}
{{Nootropics}}{{Racetams}}{{Ionotropic glutamate receptor modulators}}{{Use dmy dates|date=September 2010}}

3 : Acetamides|AMPA receptor positive allosteric modulators|Racetams
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