Vinpocetine: Difference between revisions

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== Controlled clinical trials ==
== Controlled clinical trials ==


As of 2003 only three controlled [[clinical trial]]s had tested "older adults with memory problems",<ref name=McDaniel2003/> and these studies had promising results.<ref name=McDaniel2003>{{cite journal |author=McDaniel MA, Maier SF, Einstein GO |title="Brain-specific" nutrients: a memory cure? |journal=Nutrition |volume=19 |issue=11-12 |pages=957–75 |year=2003 |pmid=14624946 |doi= |url=}} [http://www.psychologicalscience.org/journals/pspi/pdf/pspi312.pdf Free full-text].</ref>
As of 2003 only three controlled [[clinical trial]]s had tested "older adults with memory problems",<ref name=McDaniel2003/> and these studies had promising results.<ref name=McDaniel2003>{{cite journal |author=McDaniel MA, Maier SF, Einstein GO |title="Brain-specific" nutrients: a memory cure? |journal=Nutrition |volume=19 |issue=11-12 |pages=957–75 |year=2003 |pmid=14624946 |doi= |url=}} [http://www.psychologicalscience.org/journals/pspi/pdf/pspi312.pdf Free full-text].</ref> However, a 2003 Cochrane review concluded that the results were inconclusive.<ref name=Szatmari2003>{{cite journal |author=Szatmari SZ, Whitehouse PJ |title=Vinpocetine for cognitive impairment and dementia |journal=Cochrane Database Syst Rev |volume= |issue=1 |pages=CD003119 |year=2003 |pmid=12535455 |doi=10.1002/14651858.CD003119 |url=}}</ref>


As of 2003 only one study from 1985<ref>{{cite journal |author=Subhan Z, Hindmarch I |title=Psychopharmacological effects of vinpocetine in normal healthy volunteers |journal=Eur. J. Clin. Pharmacol. |volume=28 |issue=5 |pages=567–71 |year=1985 |pmid=3899677 |doi=10.1007/BF00544068 |url=}}</ref> had tested young, healthy adults, but this study had only 12 subjects and used a very short treatment period.<ref name=McDaniel2003/>
As of 2003 only one study from 1985<ref>{{cite journal |author=Subhan Z, Hindmarch I |title=Psychopharmacological effects of vinpocetine in normal healthy volunteers |journal=Eur. J. Clin. Pharmacol. |volume=28 |issue=5 |pages=567–71 |year=1985 |pmid=3899677 |doi=10.1007/BF00544068 |url=}}</ref> had tested young, healthy adults, but this study had only 12 subjects and used a very short treatment period.<ref name=McDaniel2003/>
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==Side-effects==
==Side-effects==


Side effects of vinpocetine may include indigestion, nausea, dizziness, anxiety, facial flushing, insomnia, headache, drowsiness and dry mouth. Vinpocetine may also cause a temporary drop in blood pressure. <ref>http://altmedicine.about.com/od/herbsupplementguide/a/vinpocetine.htm </ref>
Side effects of vinpocetine may include indigestion, nausea, dizziness, anxiety, facial flushing, insomnia, headache, drowsiness and dry mouth. Vinpocetine may also cause a temporary drop in blood pressure.<ref>http://altmedicine.about.com/od/herbsupplementguide/a/vinpocetine.htm </ref> In clinical trials adverse effects have been reported infrequently, but the trials were not long-term.<ref name=Szatmari2003>


The safety of vinpocetine in pregnant women has not been evaluated.
The safety of vinpocetine in pregnant women has not been evaluated.

Revision as of 19:15, 16 July 2009

Vinpocetine
Clinical data
Pregnancy
category
  • not recommended
Routes of
administration		oral, intravenous
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability56.6 +/- 8.9%
Metabolismhepatic
Elimination half-life2.54 +/- 0.48 hours
Excretionrenal
Identifiers
  • (3α,16α)-Eburnamenine-14-carboxylic acid ethyl ester
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.050.917 Edit this at Wikidata
Chemical and physical data
FormulaC22H26N2O2
Molar mass350.454 g/mol g·mol−1

Vinpocetine (brand names: Cavinton, Intelectol; chemical name: ethyl apovincaminate) is a semisynthetic derivative alkaloid of vincamine (sometimes described as "a synthetic ethyl ester of apovincamine"),[1] an extract from the periwinkle (plant) Vinca minor.

Vinpocetine is reported to have cerebral blood-flow enhancing[2] and neuroprotective effects,[3] and is used as a drug in Eastern Europe for the treatment of cerebrovascular disorders and age-related memory impairment.[4]

Vinpocetine is widely marketed as a supplement for vasodilation and as a nootropic for the improvement of memory. In other words, Vinpocetine helps support brain function such as enhancing concentration and memory by activating cerebral metabolism. There exists anecdotal report of uncomfortable adverse reactions to vinpocetine in a small subset of users. A low initial dosage is often recommended.

Controlled clinical trials

As of 2003 only three controlled clinical trials had tested "older adults with memory problems",[5] and these studies had promising results.[5] However, a 2003 Cochrane review concluded that the results were inconclusive.[6]

As of 2003 only one study from 1985[7] had tested young, healthy adults, but this study had only 12 subjects and used a very short treatment period.[5]

Use as a Vasodilator

Vinpocetine widely used in the body building community as an vasodilator. However, no studies have been conducted on the effectiveness of vinpocetine on performance enhancement during exercise.

Mechanism of Action

Vinpocetine has been shown to selectively inhibit voltage-sensitive Na+ channels, resulting in a dose-dependent decrease in evoked extracellular Ca+ ions in striatal nerve endings.[8] The Na+ channel inhibiting properties of vinpocetine are thought to contribute to a general neuroprotective effect through blockade of excitotoxicity and attenuation of neuronal damage induced by cerebral ischemia/reperfusion.[9]

Vinpocetine is also a phosphodiesterase (PDE) type-1 inhibitor,[10] (with an IC50 of approximately 10-5 M.) leading to increases in intracellular levels of cyclic guanosine 3'5'-monophosphate (cGMP), an action that has been attributed to the vasorelaxant effects of vinpocetine on cerebral smooth muscle tissue.[11][12]

Increases in neuronal levels of DOPAC, a metabolic breakdown product of dopamine, have been shown to occur in striatal isolated nerve endings as a result of exposure to vinpocetine.[13] Such an effect is consistent with the biogenic pharmacology of reserpine, a structural relative of vinpocetine, which depletes catecholamine levels and may cause depression as a side-effect of the cardiovascular and anti-psychotic effects.[14]

Side-effects

Side effects of vinpocetine may include indigestion, nausea, dizziness, anxiety, facial flushing, insomnia, headache, drowsiness and dry mouth. Vinpocetine may also cause a temporary drop in blood pressure.[15] In clinical trials adverse effects have been reported infrequently, but the trials were not long-term.Cite error: A <ref> tag is missing the closing </ref> (see the help page). a condition in which granulocytyes - an important type of white blood cell, are markedly decreased. Some people have anecdotally noted that their continued use of vinpocetine reduces immune function. Commission E warned that vinpocetine reduced immune function and could cause apoptosis in the long term. [16]

Other Vinca alkaloids Vincristine and Vinblastine are powerful chemotherapeutic agents which impair formation of microtubules. This means Vinpocetine which may have similar effects needs further testing in the minds of many physicians before it should be used for any particular purpose, and the case of agranulocytosis mentioned above is very concerning from a clinician's standpoint.

Dosage

It is recommended that first-time users ingest only 2-5 mg of vinpocetine with meals to make sure they are not hypersensitive to it. Users may then increase the dosage to 10-40 mg a day (which may, although very rarely, cause some light side-effects).

External links

References

  1. ^ Lörincz C, Szász K, Kisfaludy L. "The synthesis of ethyl apovincaminate." Arzneimittel-forschung 1976;26(10a):1907. PMID: 1037211.
  2. ^ Szilágyi G, Nagy Z, Balkay L, Boros I, Emri M, Lehel S, Márián T, Molnár T, Szakáll S, Trón L, Bereczki D, Csiba L, Fekete I, Kerényi L, Galuska L, Varga J, Bönöczk P, Vas A, Gulyás B. "Effects of vinpocetine on the redistribution of cerebral blood flow and glucose metabolism in chronic ischemic stroke patients: a PET study." Journal of Neurological Sciences 2005 Mar 15;229-230:275-84. Epub 2005 Jan 8. PMID: 15760651.
  3. ^ Dézsi L, Kis-Varga I, Nagy J, Komlódi Z, Kárpáti E. "[Neuroprotective effects of vinpocetine in vivo and in vitro. Apovincaminic acid derivatives as potential therapeutic tools in ischemic stroke]." Acta Pharmaceutica Hungarica 2002;72(2):84-91. 12498034
  4. ^ "Vinpocetine. Monograph." Alternative Medicine Review 2002 Jun;7(3):240-3, pp. 240. PMID: 12126465.
  5. ^ a b c McDaniel MA, Maier SF, Einstein GO (2003). ""Brain-specific" nutrients: a memory cure?". Nutrition. 19 (11–12): 957–75. PMID 14624946.{{cite journal}}: CS1 maint: multiple names: authors list (link) Free full-text.
  6. ^ Szatmari SZ, Whitehouse PJ (2003). "Vinpocetine for cognitive impairment and dementia". Cochrane Database Syst Rev (1): CD003119. doi:10.1002/14651858.CD003119. PMID 12535455.
  7. ^ Subhan Z, Hindmarch I (1985). "Psychopharmacological effects of vinpocetine in normal healthy volunteers". Eur. J. Clin. Pharmacol. 28 (5): 567–71. doi:10.1007/BF00544068. PMID 3899677.
  8. ^ Sitges M, Galván E, Nekrassov V. "Vinpocetine blockade of sodium channels inhibits the rise in sodium and calcium induced by 4-aminopyridine in synaptosomes." Neurochemistry International 2005 Jun;46(7):533-40. PMID: 15843047.
  9. ^ Adám-Vizi V. "[Neuroprotective effect of sodium channel blockers in ischemia: the pathomechanism of early ischemic dysfunction]." Orvosi Hetilap 2000 Jun 4;141(23):1279-86. PMID: 10905082
  10. ^ Hagiwara M, Endo T, Hidaka H. "Effects of vinpocetine on cyclic nucleotide metabolism in vascular smooth muscle." Biochemical Pharmacology 1984 Feb 1;33(3):453-7. PMID: 6322804.
  11. ^ Truss MC, Uckert S, Stief CG, Forssmann WG, Jonas U. "Cyclic nucleotide phosphodiesterase (PDE) isoenzymes in the human detrusor smooth muscle. II. Effect of various PDE inhibitors on smooth muscle tone and cyclic nucleotide levels in vitro." Urological Research 1996;24(3):129-34. PMID: 8839479.
  12. ^ Gurkovskaia AV, Gokina NI, Buryĭ VA, Shuba MF. "[Electrophysiological analysis of the action of kavinton on the smooth muscles]." Biull Eksp Biol Med. 1987 Jan;103(1):68-71. PMID: 3801654.
  13. ^ Trejo F, Nekrassov V, Sitges M. "Characterization of vinpocetine effects on DA and DOPAC release in striatal isolated nerve endings." Brain Research 2001 Aug 3;909(1-2):59-67. PMID: 11478921.
  14. ^ Ibid.
  15. ^ http://altmedicine.about.com/od/herbsupplementguide/a/vinpocetine.htm
  16. ^ The Complete German Commission E Monographs, Therapeutic Guide to Herbal Medicines, 1st ed. 1998, Integrative Medicine Communications, pub; Bk&CD-Rom edition, 1999.
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