Vinpocetine is reported to have cerebral blood-flow enhancing and neuroprotective effects, and is used as a drug in Eastern Europe for the treatment of cerebrovascular disorders and age-related memory impairment.
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 recommended.
Vinpocetine widely used in the body building community as an antivasoconstrictor. However, no studies have been conducted on the effectiveness of vinpocetine on performance enhancement during exercise.
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. 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.
Vinpocetine is also a phosphodiesterase (PDE) type-1 inhibitor, (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.
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. 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.
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. Anecdotal evidence has suggested 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.
The safety of vinpocetine in pregnant women has not been evaluated.
Vinpocetine has been implicated in one case to induce agranulocytosis, 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.
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).
Role of sodium channel inhibition in neuroprotection: effect of vinpocetine.(on regional cerebral blood flow)
Feb 01, 2001; Role of sodium channel inhibition in neuroprotection: effect of vinpocetine. Bonoczk P, Gulyas B, Adam-Vizi V, et al. Brain Res...