NATURAL PRODUCTS

Ginkgo biloba

Ginkgo biloba has had much coverage in the press concerning potentially dangerous drug interactions.  While the stories were sensationalist and pointed out a problem with a lack of knowledge of natural products by healthcare providers, it also pointed out the potential danger of taking natural products.

Ginkgo biloba has membrane stabilizing effects and appears to improve glucose utilization in animals and tissue tolerance to low oxygen (hypoxia).  It appears to reduce blood viscosity, which means blood can flow increase because it is easier for the heart to pump.  This effect may be partially responsible for its memory enhancing effects, by providing more oxygen to the brain.

Ginkgo biloba’s prime use has been to improve memory and concentration and to help in Alzheimer’s disease.  Its other uses include helping with:  Intermittent claudication (pain in the lower legs, especially when walking, due to insufficient blood flow), tinnitus (ringing in the ears due to vascular problems), and vertigo of vascular origin.

Ginkgo biloba is contraindicated (should be avoided) in any bleeding condition and with any anticoagulant or antiplatelet drug.   Therefore, it must not be used without physician supervision by anybody taking Coumadin, Aspirin, Trental, Plavix,  Persantine, Ticlid, NSAIDs (Motrin, Naprosyn, Advil, Aleve, Indocin, etc.), and injectable heparins, because it inhibits platelet aggregating factor and platelet function, which can increase the potential to bleed.  This interaction may also occur with Pletal, for intermittent claudication, and with the new COX-2 inhibitors for arthritis, like Celebrex and Vioxx, which are also NSAIDs.  Ginkgo biloba should be avoided in people with hemophilia A, hemophilia B, and Von Willebrand disease, because it can potentially lead to an uncontrolled bleed that may require an immediate infusion of blood factors.  There have also been reports that it was responsible for cerebral hemorrhages, but no controlled study has been done, probably for ethical reasons.

Platelet aggregating factor (PAF), which is blocked by the ginkgolide B component from Ginkgo biloba extract, is involved with ovulation and fertilization.   Studies have shown that ginkgolide B can also interfere with implantation of the fertilized egg (O'Neill, C.:  A physiological role for PAF in the stimulation of mammalian embryonic development.  Trends Pharmacol. Sci., 1991, 12:82-84.   Even though these were animal studies, it is postulated that a similar effect occurs in humans.  Since the safety of natural products during pregnancy is unknown, they should be avoided anyway.  Ginkgo biloba may very well interfere with or prevent pregnancy.

The typical daily dose of Ginkgo biloba is 120 mg of the dried extract divided and taken 2 or 3 times a day.

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Legal Info:  Solumedia is not responsible for errors or omissions.  The information provided on the natural product pages is only a guideline based on current literature and the pharmacological action of these products.  It should not be used as the sole source of information on these products.  Many of the drug interactions listed are not found in current literature but are based on likely interactions due to the actions of the interacting drugs.  It is recommended that a qualified and licensed healthcare professional be consulted for additional information.  Although the information provided is from reliable sources, Solumedia has no liability.  This information is provided only as a service.

This page was last updated on 04/29/05.