Piracetam

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Piracetam
Systematic (IUPAC) name
2-oxo-1-pyrrolidineacetamide
Identifiers
CAS number 7491-74-9
ATC code N06BX03
PubChem 4843
Chemical data
Formula C6H10N2O2 
Mol. mass 142.156 g/mol
Pharmacokinetic data
Bioavailability ~100 %
Metabolism  ?
Half life 4-5 hours
Excretion Urinary
Therapeutic considerations
Pregnancy cat.

?
Legal status

UK: POM; legal to import
Orphan drug
Routes Oral and parenteral

Piracetam (brand name: Nootropil®, Myocalm®), is a cerebral function regulating drug which is claimed to be able to enhance cognition as well as slow down brain aging. Piracetam's chemical name is 2-oxo-pyrrolidone, or 2-oxo-1-pyrrolidine acetamide. Piracetam is a cyclic derivative of GABA. It is one of the racetams, and is similar to the amino acid pyroglutamate. Though rare in the United States, piracetam is commonly prescribed in Europe for a variety of conditions.

Contents

[edit] Effects

Several meta-reviews of literature on piracetam indicate that piracetam increases performance on a variety of cognitive tasks among dyslexic children, though this may reflect its enhancement of cross-hemispheric communication and of cognitive function in general, rather than a specific improvement in whatever causes dyslexia. Piracetam also seems to inhibit brain damage caused by a variety of factors including hypoxia and excessive alcohol consumption.[1][2]

Piracetam has been studied in an extensive number of clinical experiments, and has shown positive results in the treatment of post-stroke aphasia, epilepsy, cognitive decline following heart and brain surgery, dementia,[3] and myoclonus,[4][5]and some believe that understanding the mechanism through which it works can teach us about the role of inter-hemispheric communication in the brain.[citation needed]

Some dosages of piracetam have shown positive effects on normal volunteers' mental performance (such as on verbal learning)--though the effects found in one (double blind) study took two weeks to show up.[6] [7]

[edit] Mechanisms of action

The mechanism of action of piracetam is not known.[8] It has been found to increase blood flow and oxygen consumption in parts of the brain.[9]

Piracetam may facilitate movement of information between the brain's two hemispheres via the corpus callosum, and improves the function of the neurotransmitter acetylcholine via muscarinic cholinergic (ACh) receptors which are implicated in memory processes.[10] 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.[11][12]Finally, Piracetam may exert its global effect on brain neurotransmission via modulation of ion channels (i.e., Ca2+, K+).[13] It has been found to increase oxygen consumption in the brain.

[edit] History

Piracetam was first synthesized in 1964 by scientists at the Belgian pharmaceutical company UCB led by Dr Corneliu E. Giurgea. The drug was the first of the so-called nootropics ("smart drugs" or "cognitive enhancers"), that is, substances which purportedly enhance mental performance. The term nootropic was coined by Giurgea. Nootropil was launched clinically by UCB in the early 1970s and remains an important product of that company in Europe.

[edit] Approval and usage

Piracetam is primarily used in Europe. Piracetam is legal to import into the United Kingdom and the United States for personal use with or without prescription as with other prescription-only drugs. As of June of 2006, piracetam is not regulated in the United States (it is neither a controlled substance nor a prescription drug but instead sold as a dietary supplement). It has become popular as a cognitive enhancement drug among students, who often buy it in bulk as a powder and then consume it with orange juice to mask the strong, bitter taste. It is used by parents as a treatment for childhood autism, though no study has yet produced results which would support such a use.

Piracetam is useful as a long term treatment for clotting, coagulation, and vasospastic disorders such as Raynaud's phenomenon[14] and deep vein thrombosis[15][16] It is an extremely safe anti-thrombotic agent which operates through the novel mechanism of inhibiting platelet aggregation and enhancing blood cell deformability.[17] Because traditional anti-thrombotic drugs operate through the separate mechanism of inhibiting clotting factors, co-adminsitration of piracetam has been shown to highly complement the efficacy and safety of traditional Warfarin/Heparin anti-coagulation therapy.[18] The most effective treatment range for this use is a daily dose of 4.8 to 9.6 grams divided into three daily doses at 8 hours apart.[19] Piracetam is currently being investigated as a complement or alternative to Warfarin as a safe and effective long term treatment for recurring deep vein thrombosis.[20]

[edit] Dosage

Piracetam is usually supplied in 800 mg tablets or capsules. Some bulk or nutritional suppliers supply it in a powder form. The recommended dosage varies based on the indication, usually ranging from 1.6-9.6 grams daily (2-12 pills daily). Some people report faster results when taking 1-2 pills every hour for 4-6 hours or taking 4-8 pills at once for the first few days to notice an effect.

For blood coagulation, clotting, and vasospastic disorders such as Raynaud's phenomenon or deep vein thrombosis, the most effective treatment range is a daily dose of 4.8 to 9.6 grams divided into three daily doses at 8 hours apart.[21][22][23]

It has been studied up to 45 grams daily without major side effects.[citation needed]

It has no known LD-50 in humans when taken orally.[24]

[edit] Contraindications

Piracetam is contra-indicated in patients with severe renal impairment (renal creatinine clearance of less than 20 ml per minute), hepatic impairment and to those under 16 years of age. It is also contraindicated in patients with cerebral haemorrhage and in those with hypersensitivity to piracetam, other pyrrolidone derivatives or any of the excipients .

[edit] Special warnings and precautions for use

Due to the effect of piracetam on platelet aggregation, caution is recommended in patients with underlying disorders of haemostasis, major surgery or severe haemorrhage.

Abrupt discontinuation of treatment should be avoided as this may induce myoclonic or generalised seizures in some myoclonic patients.

As piracetam is almost exclusively excreted by the kidneys caution should be exercised in treating patients with known renal impairment. In renally impaired and elderly patients, an increase in terminal half-life is directly related to renal function as measured by creatinine clearance. Dosage adjustment is therefore required in those with mild to moderate renal impairment and elderly patients with diminished renal function.

[edit] Undesirable effects

Piracetam has been found to have very few side effects, and those it has are typically "few, mild, and transient."[25]

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.[26]

Many other studies have likewise found piracetam to be well-tolerated.[27][28]

Headache from use of piracetam may be aleviated by coadministration of an acetylcholine biosynthetic precursor, such as choline bitarate, choline citrate, or lecithin.[citation needed]

Many users report decreased levels of tolerance for alcohol and cannabis when taking Piracetam.

[edit] References

  1. ^ "Can nootropic drugs be effective against the impact of ethanol teratogenicity on cognitive performance?" Eur Neuropsychopharmacol. 2001 Feb;11(1):33-40.
  2. ^ "Piracetam and vinpocetine exert cytoprotective activity and prevent apoptosis of astrocytes in vitro in hypoxia and reoxygenation." Neurotoxicology. 2002 May;23(1):19-31.
  3. ^ "Clinical efficacy of piracetam in cognitive impairment: a meta-analysis."Dement Geriatr Cogn Disord. 2002;13(4):217-24.
  4. ^ "Long-term efficacy and safety of piracetam in the treatment of progressive myoclonus epilepsy."Arch Neurol. 2001 May;58(5):781-6.
  5. ^ Effectiveness of piracetam in cortical myoclonus." Mov Disord. 1993;8(1):63-8.
  6. ^ "Increase in the power of human memory in normal man through the use of drugs." Dimond SJ,Brouwers EM, Psychopharmacology (Berl). 1976 Sep 29;49(3):307-9.
  7. ^ http://www.antiaging-systems.com/extract/nootr.htm
  8. ^ "Piracetam and other structurally related nootropics." Brain Res Brain Res Rev. 1994 May;19(2):180-222.
  9. ^ "Cerebral blood flow effects of piracetam, pentifylline, and nicotinic acid in the baboon model compared with the known effect of acetazolamide." Arzneimittelforschung. 1996 Sep;46(9):844-7.
  10. ^ "Piracetam--an old drug with novel properties?" Acta Pol Pharm. 2005 Sep-Oct;62(5):405-9.
  11. ^ "Piracetam--an old drug with novel properties?" Acta Pol Pharm. 2005 Sep-Oct;62(5):405-9.
  12. ^ "Piracetam: novelty in a unique mode of action." Pharmacopsychiatry. 1999 Mar;32 Suppl 1:2-9.
  13. ^ "Piracetam and other structurally related nootropics." Brain Res Brain Res Rev. 1994 May;19(2):180-222.
  14. ^ "Treatment of the Raynaud's phenomenon with piracetam." Arzneimittelforschung. 1993 May;43(5):526-35.
  15. ^ "Piracetam--an old drug with novel properties?" Acta Pol Pharm. 2005 Sep-Oct;62(5):405-9.
  16. ^ "Platelet anti-aggregant and rheological properties of piracetam. A pharmacodynamic study in normal subjects." Arzneimittelforschung. 1993 Feb;43(2):110-8.
  17. ^ "Piracetam--an old drug with novel properties?" Acta Pol Pharm. 2005 Sep-Oct;62(5):405-9.
  18. ^ "The treatment of severe or recurrent deep venous thrombosis. Beneficial effect of the co-administration of antiplatelet agents with or without rheological effects, and anticoagulants." Thromb Res. 1995 Jun 15;78(6):469-82.
  19. ^ "Platelet anti-aggregant and rheological properties of piracetam. A pharmacodynamic study in normal subjects." Arzneimittelforschung. 1993 Feb;43(2):110-8.
  20. ^ "Platelet anti-aggregant and rheological properties of piracetam. A pharmacodynamic study in normal subjects." Arzneimittelforschung. 1993 Feb;43(2):110-8.
  21. ^ "Treatment of the Raynaud's phenomenon with piracetam." Arzneimittelforschung. 1993 May;43(5):526-35.
  22. ^ "Piracetam--an old drug with novel properties?" Acta Pol Pharm. 2005 Sep-Oct;62(5):405-9.
  23. ^ "Platelet anti-aggregant and rheological properties of piracetam. A pharmacodynamic study in normal subjects." Arzneimittelforschung. 1993 Feb;43(2):110-8.
  24. ^ "Piracetam and other structurally related nootropics." Brain Res Brain Res Rev. 1994 May;19(2):180-222.
  25. ^ "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." Neurol Neurosurg Psychiatry. 1998 Mar;64(3):344-8.
  26. ^ "The clinical safety of high-dose piracetam--its use in the treatment of acute stroke." Pharmacopsychiatry. 1999 Mar;32 Suppl 1:33-7.
  27. ^ "Long-term efficacy and safety of piracetam in the treatment of progressive myoclonus epilepsy." Arch Neurol. 2001 May;58(5):781-6.
  28. ^ "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." J Neurol Neurosurg Psychiatry. 1998 Mar;64(3):344-8.

[edit] See also

[edit] External links

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