Vinpocetine
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Vinpocetine
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| Systematic (IUPAC) name | |
| (3α,16α)-Eburnamenine-14-carboxylic acid ethyl ester | |
| Identifiers | |
| CAS number | |
| ATC code | N06 |
| PubChem | |
| Chemical data | |
| Formula | C22H26N2O2 |
| Mol. mass | 350.454 g/mol |
| Pharmacokinetic data | |
| Bioavailability | 56.6 +/- 8.9% |
| Metabolism | hepatic |
| Half life | 2.54 +/- 0.48 hours |
| Excretion | renal |
| Therapeutic considerations | |
| Pregnancy cat. |
not recommended |
| Legal status |
OTC |
| Routes | oral, intravenous |
Vinpocetine (brand names: Cavinton, Intelectol; chemical name: ethyl apovincaminate) is a semisynthetic derivative alkaloid of vincamine,[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. There exists anecdotal report of uncomfortable adverse reactions to vinpocetine in a small subset of users. A low initial dosage is often recomended.
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[edit] Possible Nootropic Properties
A number of studies on healthy volunteers have demostrated vinpocetine may elicit improvement on some aspects of memory. [5] [6] The degree which the nootropic effects of vinopocetine are mediated by mechanisms beyond vasodilation are currently unknown.
[edit] Use as a Vasodilator
Vinpocetine widely used in the body building community as a vasodilator. However, no studies have been conducted on the effectiveness of vinpocetine on performance enhancement during exercise. There exists anecdotal evidence that a small subset of users may experience adverse reactions. Due to the possibility of adverse reactions a low initial dose is typically recommended. The small size of existing studies precludes conclusion on the prevalence or severity of possible adverse reactions in vinopocetine usage.
[edit] 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.[7] 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.[8]
Vinpocetine is also a phosphodiesterase (PDE) type-1 inhibitor,[9] (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.[10][11]
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.[12] 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.[13]
[edit] Side-effects
No adverse reactions to vinpocetine have been reported in human trials. Due to the small sample size of existing trials the prevalence of adverse reactions is still unknown although thought to be rare.
Stomach/ GI upset; headache, dry mouth, rapid heart beat, low blood pressure, and rash/ hives are the main (rarely-occurring) reported side-effects.
The safety of vinopocetine in pregnant women has not been evaluated.
Vinpocetine has been implicated in one case to induce agranulocytosis,[14] a condition in which granulocytyes - an important type of white blood cell, are markedly decreased.
[edit] Dosage
It is recommended that first-time users ingest only 2-5 mg of vinpocetine to make sure they are not hypersensitive to it. Users may then increase the dosage to 10-30 mg a day (which may, although very rarely, cause some side-effects).
[edit] External links
[edit] References
- ^ Lörincz C, Szász K, Kisfaludy L. "The synthesis of ethyl apovincaminate." Arzneimittel-forschung 1976;26(10a):1907. PMID: 1037211.
- ^ 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.
- ^ 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
- ^ "Vinpocetine. Monograph." Alternative Medicine Review 2002 Jun;7(3):240-3, pp. 240. PMID: 12126465.
- ^ Psychopharmacological effects of vinpocetine in normal healthy volunteers [[1]].
- ^ Possible memory-enhancing properties of vinpocetine[[2]].
- ^ 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.
- ^ 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
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ Ibid.
- ^ Shimizu Y, Saitoh K, Nakayama M, et al. Agranulocytosis induced by vinpocetine. Medicine Online [serial online]. Available at: http://www.priory.com/med/vinpocetine.htm. Accessed March 08, 2008.
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