1. DESCRIPTION: Vinpocetine is a semi-synthetic derivative of vincamine. Vincamine is an alkaloid derived from the plant Vinca minor L., a member of the periwinkle family. Vinpocetine, as well as vincamine, are used in Europe, Japan and Mexico as pharmaceutical agents for the treatment of cerebrovascular and cognitive disorders. In the United States, vinpocetine is marketed as a dietary supplement. It is sometimes called a nootropic, meaning cognition enhancer, from the Greek noos for mind.
Vinpocetine is also known as ethyl apovincaminate; ethyl apovincaminoate; eburnamenine-14-carboxylic acid ethyl ester; 3 alpha, 16 alpha-apovincaminic acid ethyl ester; ethyl apovincamin-22-oate; and cavinton, which is sometimes used generically for a branded product with that name. Another vinca alkaloid called vinconate is also being researched as a possible cognition enhancer. The structural formula of vinpocetine is:
2. PHARMACOLOGY: Vinpocetine has several possible actions, including increasing cerebral blood flow and metabolism, anticonvulsant, cognition enhancement, neuroprotection and antioxidant. Vincamine, the parent compound of vinpocetine, is believed to be a cerebral vasodilator.
3. MECHANISM OF ACTION: Several mechanisms have been proposed for the possible actions of vinpocetine. Vinpocetine has been reported to have calcium-channel blocking activity, as well as voltage-gated sodium channel blocking activity. It has also been reported to inhibit the acetylcholine release evoked by excitatory amino acids and to protect neurons against excitotoxicity. In addition, vinpocetine has been shown to inhibit a cyclic GMP phosphodiesterase, and it is speculated that this inhibition enhances cyclic GMP levels in the vascular smooth muscle, leading to reduced resistance of cerebral vessels and increase of cerebral flow. In some studies, vinpocetine has demonstrated antioxidant activity equivalent to that of vitamin E.
4. PHARMACOKINETICS: Vinpocetine is absorbed from the small intestine, from whence it is transported to the liver via the portal circulation. From the liver via the systemic circulation, it is distributed to various tissues in the body, including the brain. Absorption of vinpocetine is significantly higher when given with food and can be up to about 60% of an ingested dose. On an empty stomach, absorption of an ingested dose can be as low as 7%. Peak plasma levels are obtained one to one and a half hours after ingestion. Extensive metabolism to the inactive apovincaminic acid occurs in the liver. Only small amounts of unmetabolized vinpocetine are excreted in the urine, the major route of excretion of apovincaminic acid. Most of a dose is excreted within 24 hours as this metabolite. The elimination half-life of vinpocetine following ingestion is one to two hours.
5. INDICATIONS AND USAGE: The primary claim made for vinpocetine is that it decreases fatality and dependency in ischemic stroke. Research results are mixed. Vinpocetine has not been helpful in Alzheimer's disease, but there is some suggestion that it might help some with other dementias and cerebral dysfunction. Very preliminary research additionally suggests that vinpocetine may help protect the eye and ear from injuries caused by trauma (and, in the case of the eye, from infection) and that it might be gastroprotective, ameliorate symptoms of motion sickness and help prevent atherosclerosis.
6. RESEARCH SUMMARY: Several small studies, in both animals and humans, have reported significant vinpocetine-associated protective effects in ischemic stroke. A review of these studies, however, found only one positive study of a truly randomized, unconfounded clinical trials that compared the effect of vinpocetine to either placebo or another reference treatment for acute stroke where treatment started no later than 14 days after stroke onset. There is currently not enough evidence to determine whether vinpocetine does or does not reduce fatalities and dependence in ischemic stroke. Further research is needed.
There is some evidence vinpocetine may be useful in some other cerebral maladies. In one multi-center, double-blind, placebo-controlled study lasting 16 weeks, 203 patients described as having mild to moderate psychosyndromes, including primary dementia, were treated with varying doses of vinpocetine or placebo. Significant improvement was achieved in the vinpocetine-treated group as measured by "global improvement" and cognitive performance scales. Three 10-milligram doses daily were as effective or more effective than three 20-milligram doses daily. Similarly good results were found in another double-blind clinical trial testing vinpocetine versus placebo in elderly patients with cerebrovascular and central nervous system degenerative disorders. Studies of Alzheimer's disease, however, have shown no vinpocetine benefit.
Some preliminary research suggests that vinpocetine may have some protective effects in both sight and hearing. One study of patients with mild burn trauma in the eyes showed that vinpocetine enhanced healing, most likely as a result of increased blood flow to the damaged tissue. Vinpocetine has also been associated with improvements seen in retinas damaged by hepatitis B virus. Damage from acoustic trauma has similarly been reduced by vinpocetine treatment.
Vinpocetine gastroprotective effects have been reported in animal models challenged with noxious agents. There are anecdotal reports that vinpocetine is protective against some of the gastric and neurological toxicity of excessive alcohol consumption.
There are some reports that vinpocetine may be an effective motion sickness preventative and some early findings in animals that it may exert some anti-atherosclerotic effects through a reported ability to decalcify cholesterol-induced atherosclerotic lesions.
7. CONTRAINDICATIONS: None known.
8. PRECAUTIONS: Pregnant women and nursing mothers should avoid vinpocetine supplements. Those with a history of allergic reactions or hypersensitivity reactions during treatment with other vinca alkaloids, such as vinblastine and vincristine, should avoid vinpocetine. Those on warfarin are advised to have their INRs (international normalized ratios) regularly monitored when using vinpocetine supplements (see Interactions). Those with hypotension or orthostatic hypotension should be cautioned that prolonged use of vinpocetine may lead to slight reductions in systolic and diastolic blood pressure.
9. ADVERSE REACTIONS: Reported adverse reactions include nausea, dizziness, insomnia, drowsiness, dry mouth, transient hypotension, transient tachycardia, pressure-type headache and facial flushing. Slight reductions in both systolic and diastolic blood pressure with prolonged use of vinpocetine have been reported, as well as slight reductions in blood glucose.
10. INTERACTIONS: Warfarin—Slight changes in prothrombin time have been noted in those adding vinpocetine to warfarin dosing. The changes appear minimal. However, regular monitoring of INR is advised in those using warfarin and vinpocetine concomitantly. There are no other known drug or nutritional supplement, herb or food interactions.
11. OVERDOSAGE: There are no reports of vinpocetine overdosage.
12. DOSAGE AND ADMINISTRATION: Vinpocetine is available as an individual supplement and in combination products. Typical doses for supplement use are 5 to 10 milligrams daily with food. Some take up to 20 milligrams daily. Higher doses are not advised.
Caution! Before starting to take this medicine, it is vital that you should consult your doctor! Do not use it on your own initiative, without medical advice.
I have been taking Vinpocetine for 5 months now one capsule a day with meal. No side effects.
Filed Under (tags):
- Agnes's blog
- Log in or register to post comments
