Wikipedia

Piracetam

Piracetam is a drug that has efficacy in cognitive disorders, vertigo, cortical myoclonus, dyslexia, and sickle cell anemia; sources differ on its usefulness for dementia.[3][4][5] Piracetam is sold as a medication in many European countries. Sale of piracetam is not illegal in the United States, although it is not regulated nor approved by the FDA, so it is legally sold for research use only.[6]

Piracetam
Clinical data
Trade namesBreinox, Dinagen, Lucetam, Nootropil, Nootropyl, Oikamid, Piracetam, others
AHFS/Drugs.comInternational Drug Names
Routes of
administration		By mouth, parenteral, inhalation
ATC code
Legal status
Legal status
  • AU: S4 (Prescription only)
  • CA: Unscheduled
  • UK: POM (Prescription only)
  • US: Unapproved "New Drug" (as defined by 21 U.S. Code § 321(p)(1)). Use in dietary supplements, food, or medicine is unlawful; otherwise uncontrolled.[1])
Pharmacokinetic data
Bioavailability~100%
Onset of actionSwiftly following administration. Food delays time to peak concentration by 1.5 h approximately to 2–3 h since dosing.[2]
Elimination half-life4–5 hours
ExcretionUrinary
Identifiers
  • 2-(2-Oxopyrrolidin-1-yl)acetamide
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.028.466 Edit this at Wikidata
Chemical and physical data
FormulaC6H10N2O2
Molar mass142.158 g·mol−1
3D model (JSmol)
Melting point152 °C (306 °F)
  • O=C1N(CC(=O)N)CCC1
  • InChI=1S/C6H10N2O2/c7-5(9)4-8-3-1-2-6(8)10/h1-4H2,(H2,7,9) checkY
  • Key:GMZVRMREEHBGGF-UHFFFAOYSA-N checkY
  (verify)

Piracetam is in the racetams group, with chemical name 2-oxo-1-pyrrolidine acetamide. It is a cyclic derivative of the neurotransmitter GABA[4] and shares the same 2-oxo-pyrrolidone base structure with pyroglutamic acid. Related drugs include the anticonvulsants levetiracetam and brivaracetam, and the putative nootropics aniracetam and phenylpiracetam.

Efficacy

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Dementia

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A 2001 Cochrane review concluded that there was not enough evidence to support piracetam for dementia or cognitive problems.[5] A 2005 review found some evidence of benefit in older subjects with cognitive impairment.[4] In 2008, a working group of the British Academy of Medical Sciences noted that many of the trials of piracetam for dementia were flawed.[7]

There is insufficient evidence of piracetam as a treatment for vascular dementia.[8]

Depression and anxiety

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Some sources suggest that piracetam's overall effect on lowering depression and anxiety is higher than on improving memory.[9] However, depression is reported to be an occasional adverse effect of piracetam.[10]

Attention deficit hyperactivity disorder (ADHD)

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Several clinical trials have looked at piracetam's efficacy as a treatment for ADHD. Many of these have found that the drug fails to deliver the same therapeutic effects as current standard treatments for the disorder.[11][unreliable source?] However, more than one study has found piracetam to be highly synergistic with standard ADHD therapies, accelerating and potentiating their therapeutic effects. One 2008 clinical trial found that the combination of piracetam and atomoxetine was more effective than atomoxetine alone.[12]

While piracetam may be an effective adjuvant therapy for ADHD (when used with specific medications), there is no evidence that it is effective when used in isolation.

Other

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Piracetam may facilitate the deformability of erythrocytes in capillary which is useful for cardiovascular disease.[4][3]

Peripheral vascular effects of piracetam have suggested its use potential for vertigo, dyslexia, Raynaud's phenomenon and sickle cell anemia.[4][3] 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]

Anti-vasospasm

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Piracetam has been found to diminish erythrocyte adhesion to vascular wall endothelium, making any vasospasm in the capillary less severe. This contributes to its efficacy in promoting microcirculation, including to the brain and kidneys.[4][3]

Side effects

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Symptoms including anxiety, insomnia, irritability, headache, agitation, tremor, and hyperkinesia are occasionally reported.[10][18][19] Other reported side effects include somnolence, weight gain, clinical depression, weakness, increased libido, and hypersexuality.[10]

According to a 2005 review, piracetam has been observed to have the following side effects: hyperkinesia, weight gain, anxiety, somnolence, depression, and weakness.[4]

Piracetam reduces platelet aggregation as well as fibrinogen concentration, and thus is contraindicated to patients with cerebral hemorrhage.[4][3]

Toxicity

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The LD50 for oral consumption in humans has not been determined.[20] The LD50 is 5.6 g/kg for rats and 20 g/kg for mice, indicating extremely low acute toxicity.[21] For comparison, in rats the LD50 of vitamin C is 12 g/kg and the LD50 of table salt is 3 g/kg.

Mechanisms of action

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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.[4] 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.[22] It is hypothesized to act on ion channels or ion carriers, thus leading to increased neuron excitability.[20] GABA brain metabolism and GABA receptors are not affected by piracetam[23]

Piracetam increases the action of the neurotransmitter acetylcholine via muscarinic cholinergic (ACh) receptors[citation needed], which are implicated in memory processes.[24] 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.[24][25] Piracetam may exert its global effect on brain neurotransmission via modulation of ion channels (i.e., Na+, K+).[20] 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.[26][27] Piracetam, while in the brain, appears to increase the synthesis of cytochrome b5,[28] 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.[26]

Piracetam inhibits N-type calcium channels. The concentration of piracetam achieved in central nervous system after a typical dose of 1200 mg (about 100 μM)[29] is much higher than the concentration necessary to inhibit N-type calcium channels (IC50 of piracetam in rat neurons was 3 μM).[30]

History

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Piracetam was first made some time between the 1950s and 1964 by Corneliu E. Giurgea.[31] There are reports of it being used for epilepsy in the 1950s.[32]

Society and culture

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In 2009 piracetam was reportedly popular as a cognitive enhancement drug among students.[33]

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Piracetam is an uncontrolled substance in the United States, meaning it is legal to possess without a license or prescription.[34] Use of piracetam in food, supplements, medical devices, insecticides, infant formula, cosmetics, animal feed, animal drugs, tobacco products, and drugs is unlawful and constitutes an act of misbranding.

Regulatory status

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In the United States, piracetam is not approved by the Food and Drug Administration.[1] Piracetam is not permitted in compounded drugs or dietary supplements in the United States.[35] Like most research chemicals, it has been available over-the-counter, self-regulated, and third-party lab tested by many U.S. companies for decades.[6] Nonetheless it is still, for the purposes of U.S. law, a "New Drug" as defined by 21 U.S. Code § 321(p)(1).

In the United Kingdom, piracetam is approved as a prescription drug[36] for adults with myoclonus of cortical origin, irrespective of cause, and should be used in combination with other anti-myoclonic therapies.[37]

In Japan, piracetam is approved as a prescription drug.[38]

In the Czech Republic, piracetam is available without prescription.[39] [40]

Piracetam has no DIN in Canada, and thus cannot be sold, but can be imported for personal use in Canada.[41]

In Hungary, piracetam was a prescription-only medication, but as of 2020, no prescription is required and piracetam is available as an over-the-counter drug under the name Memoril Mite, and is available in 600 mg pills.

See also

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  • 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.
  • Ergoloid
  • 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

References

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  1. ^ a b "Piracetam". DrugBank database.
  2. ^ Leaflet of Piracetam.
  3. ^ a b c d e "Nootropil Tablets 1200 mg". (emc). 15 February 2017. Retrieved 14 April 2019.
  4. ^ a b c d e f g h i Winblad B (2005). "Piracetam: a review of pharmacological properties and clinical uses". CNS Drug Reviews. 11 (2): 169–182. doi:10.1111/j.1527-3458.2005.tb00268.x. PMC 6741724. PMID 16007238.
  5. ^ a b Flicker L, Grimley Evans G (2001). "Piracetam for dementia or cognitive impairment". The Cochrane Database of Systematic Reviews (2): CD001011. doi:10.1002/14651858.CD001011. PMID 11405971.
  6. ^ a b Cohen PA, Zakharevich I, Gerona R (March 2020). "Presence of Piracetam in Cognitive Enhancement Dietary Supplements". JAMA Internal Medicine. 180 (3): 458–459. doi:10.1001/jamainternmed.2019.5507. PMC 6902196. PMID 31764936.
  7. ^ Horne G, et al. (May 2008). Brain science, addiction and drugs (PDF) (Report). Academy of Medical Sciences. p. 145. ISBN 978-1-903401-18-7.
  8. ^ Farooq MU, Min J, Goshgarian C, Gorelick PB (September 2017). "Pharmacotherapy for Vascular Cognitive Impairment". CNS Drugs (Review). 31 (9): 759–776. doi:10.1007/s40263-017-0459-3. PMID 28786085. S2CID 23271739. Other medications have been considered or tried for the treatment of VCI or VaD. These include [...] piracetam. There is no convincing evidence about the efficacy of these medications in the treatment of VCI.
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  11. ^ "Is Piracetam Good for ADHD? - Epimodels". 11 May 2023. Retrieved 3 August 2023.
  12. ^ Zavadenko NN, Suvorinova NI (2008). "[Atomoxetine and piracetam in the treatment of attention deficit hyperactivity disorder in children]". Zhurnal Nevrologii I Psikhiatrii imeni S.S. Korsakova. 108 (7): 43–47. PMID 18833117.
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  14. ^ Hofmeyr GJ, Kulier R (June 2012). "Piracetam for fetal distress in labour". The Cochrane Database of Systematic Reviews. 2012 (6): CD001064. doi:10.1002/14651858.CD001064.pub2. PMC 7048034. PMID 22696322.
  15. ^ Ricci S, Celani MG, Cantisani TA, Righetti E (September 2012). "Piracetam for acute ischaemic stroke". The Cochrane Database of Systematic Reviews. 2012 (9): CD000419. doi:10.1002/14651858.CD000419.pub3. PMC 7034527. PMID 22972044.
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  17. ^ Yeo SH, Lim ZI, Mao J, Yau WP (October 2017). "Effects of Central Nervous System Drugs on Recovery After Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials". Clinical Drug Investigation. 37 (10): 901–928. doi:10.1007/s40261-017-0558-4. PMID 28756557. S2CID 6520934.
  18. ^ Chouinard G, Annable L, Ross-Chouinard A, Olivier M, Fontaine F (1983). "Piracetam in elderly psychiatric patients with mild diffuse cerebral impairment". Psychopharmacology. 81 (2): 100–106. doi:10.1007/BF00429000. PMID 6415738. S2CID 32702769.
  19. ^ Hakkarainen H, Hakamies L (1978). "Piracetam in the treatment of post-concussional syndrome. A double-blind study". European Neurology. 17 (1): 50–55. doi:10.1159/000114922. PMID 342247.
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  21. ^ "Piracetam Material Safety Sheet" (PDF). Spectrum.
  22. ^ Ahmed AH, Oswald RE (March 2010). "Piracetam defines a new binding site for allosteric modulators of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors". Journal of Medicinal Chemistry. 53 (5): 2197–2203. doi:10.1021/jm901905j. PMC 2872987. PMID 20163115.
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  24. ^ a b Winnicka K, Tomasiak M, Bielawska A (2005). "Piracetam--an old drug with novel properties?". Acta Poloniae Pharmaceutica. 62 (5): 405–409. PMID 16459490.
  25. ^ Müller WE, Eckert GP, Eckert A (March 1999). "Piracetam: novelty in a unique mode of action". Pharmacopsychiatry. 32 (Suppl 1): 2–9. doi:10.1055/s-2007-979230. PMID 10338102. S2CID 5960250.
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  27. ^ Nickolson VJ, Wolthuis OL (October 1976). "Effect of the acquisition-enhancing drug piracetam on rat cerebral energy metabolism. Comparison with naftidrofuryl and methamphetamine". Biochemical Pharmacology. 25 (20): 2241–2244. doi:10.1016/0006-2952(76)90004-6. PMID 985556.
  28. ^ Tacconi MT, Wurtman RJ (1986). "Piracetam: physiological disposition and mechanism of action". Advances in Neurology. 43: 675–685. PMID 3946121.
  29. ^ Yeh HH, Yang YH, Ko JY, Chen SH (July 2006). "Rapid determination of piracetam in human plasma and cerebrospinal fluid by micellar electrokinetic chromatography with sample direct injection". Journal of Chromatography A. 1120 (1–2): 27–34. doi:10.1016/j.chroma.2005.11.071. PMID 16343512.
  30. ^ Bravo-Martínez J, Arenas I, Vivas O, Rebolledo-Antúnez S, Vázquez-García M, Larrazolo A, García DE (October 2012). "A novel CaV2.2 channel inhibition by piracetam in peripheral and central neurons". Experimental Biology and Medicine. 237 (10): 1209–1218. doi:10.1258/ebm.2012.012128. PMID 23045722. S2CID 25909697.
  31. ^ Li JJ, Corey EJ (2013). Drug Discovery: Practices, Processes, and Perspectives. John Wiley & Sons. p. 276. ISBN 9781118354469.
  32. ^ Schmidt D, Shorvon S (2016). The End of Epilepsy?: A History of the Modern Era of Epilepsy Research 1860-2010. Oxford University Press. p. 69. ISBN 9780198725909.
  33. ^ Medew J (1 October 2009). "Call for testing on 'smart drugs'". Fairfax Media. Retrieved 29 May 2014.
  34. ^ "Erowid Piracetam Vault: Legal Status".
  35. ^ Bellamy J (26 September 2019). "FDA proposes ban on curcumin and other naturopathic favorites in compounded drugs". Science-Based Medicine.
  36. ^ "Parallel import (PI) licences granted in June 2015" (PDF). UK Government.
  37. ^ "Nootropil Tablets 800 mg". (emc).
  38. ^ "UCB's piracetam approved in Japan". The Pharma Letter. 25 November 1999.
  39. ^ "Fulltext".
  40. ^ https://www.sukl.cz/uploads/Prehledy_a_databaze/SCAU081231i.txt?highlightWords=piracetam [bare URL]
  41. ^ "Guidance Document on the Import Requirements for Health Products under the Food and Drugs Act and its Regulations (GUI-0084)". Health Canada / Health Products and Food Branch Inspectorate. 1 June 2010. Archived from the original on 3 December 2017. Retrieved 15 December 2019.
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