Ginkgo is a popular herbal medication and extract derived from the leaves and seeds of the tree Ginkgo biloba. Ginkgo has not been implicated in causing liver injury.
Ginkgo (ging' koe) is a widely used herbal derived from the leaves and seeds of the Ginkgo biloba tree, a “living fossil”, being the only extant species of what was a large order of plants (Ginkgoales) more than 200 million years ago. Ginkgo is native to central China, but has been introduced worldwide. The word ginkgo derives from a Japanese approximation of the Chinese word for “silver apricot” referring to the tree’s fruit. Extracts from ginkgo leaves and seeds were used in traditional Chinese medicine for centuries for a multitude of illnesses and conditions. Ginkgo extracts contain multiple compounds, but ginkgolides and bilobalide are unique to this herb. Ginkgo extracts have been shown to have antioxidant, antiinflammatory and antihistaminic activity. Current uses are many and include dementia, memory loss, headache, dizziness, tinnitus, hearing problems, difficulty concentrating, mood disturbances, peripheral vascular disease, asthma, and bronchitis. Ginkgo is purported to increase mental acuity and delay the effects of aging on the brain, as well as improve peripheral circulation, prevent macular degeneration and decrease symptoms of claudication and Raynaud’s syndrome. Ginkgo leaf extract is also used in foods, cosmetics, and skin lotions. The scientific bases for the purported effects of ginkgo are not well established and clinical trials have shown no or only modest clinical effects in dementia, claudication and tinnitus. Ginkgo is available in a variety of formulations (tablets, capsules, powder, teas, and lotions) and the typical oral dosage is 120 to 240 mg per day in 2 to 3 divided doses. Side effects of ginkgo are uncommon and mild, and include gastrointestinal upset, nausea, diarrhea, headache, dizziness, increased bleeding tendency and rash. In clinical trials, both serious and common side effects have been no more frequent with ginkgo than placebo.
Despite wide spread use, ginkgo has not been specifically linked to liver injury, either in the form of transient serum enzyme elevations or clinically apparent acute liver injury. Indeed, ginkgo is sometimes used to treat acute or chronic liver injury. Gingko demostrates some degree of inhibition of cytochrome P450 activity in vitro, but in doses used in humans it appears to have little effect on drug metabolism. Several instances of excessive bleeding during therapy with ginkgo have been attributed to drug interactions with antiplatelet medications or anticoagulants.
Likelihood score: E (unlikely cause of clinically apparent liver injury).
Other Names: Maidenhair tree, fossil tree, kew tree, Japanese silver apricot
REPRESENTATIVE TRADE NAMES
Ginkgo – Generic
Herbal and Dietary Supplements
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References updated: 14 March 2018
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