Medicinal parts of ginkgo include dried or fresh leaves and the seeds separated from the fleshy outer layer. The flavono ids and terpenoids of ginkgo extracts are considered antioxidants that serve as free radical scavengers. Other suggested mechanisms of action include arterial vasodilation, increased tissue perfusion, increased cerebral blood flow, decreased arterial spasm, decreased blood viscosity, and decreased platelet aggregation. In Germany, standardized ginkgo extracts are required to contain 22% to 27% ginkgo flavonoids and 5% to 7% terpenoids.
Ginkgo may be effective in the management of cerebral insufficiency, dementia, and circulatory disorders. It's available as tablets, capsules, and liquid preparations. Common trade names include Bioginkgo, Gincosan, Ginkgo Go!, Ginkgo Liquid Extract Herb, Ginkgo Nut, Ginkgo Power, Ginkgo Capsules, Ginkyo, and Quanterra Mental Sharpness.
Gingko is primarily used to manage cerebral insufficiency, dementia, and circulatory disorders such as intermittent claudication. It's also used to treat headaches, asthma, colitis, impotence, depression, altitude sickness, tinnitus, cochlear deafness, vertigo, premenstrual syndrome, macular degeneration, diabetic retinopathy, and allergies.
Gingko is used as an adjunctive treatment for pancreatic cancer and schizo phrenia. It's also used in addition to physical therapy for Fontaine stage IIb peripheral arterial disease to decrease pain during ambulation.
Tablets and capsules: 40 to 80 mg by mouth three times a day
Tincture (1:5 tincture of the crude ginkgo leaf): 0.5 ml by mouth three times a day.
Adverse effects of gingko include headache, dizziness, subarachnoid hemorrhage, palpitations, nausea, vomiting, flatulence, diarrhea, and allergic reaction. Administration with anticoagulants, antiplatelets, high-dose vitamin E, and garlic and other herbs that increase bleeding time may increase the risk of bleeding. Ginkgo may potentiate the activity of monoamine oxidase inhibitors. Ginkgo extracts may reverse the sexual dysfunction associated with selective serotonin reuptake inhibitors.
Pregnant or breast-feeding women should avoid use of gingko. Patients with a history of an allergic reaction to ginkgo or any of its components should avoid Use, as should patients with risk factors associated with intracranial hemorrhage hyPertension, diabetes). Patients receiving an antiplatelet or an anticoagulant should avoid use because of the increased rise of bleeding. Gingko should be avoided in the perioperative period and before childbirth.
Safety Risk Gingko has been known to cause GI problems, dizziness, and serious bleeding.
Ginkgo extracts are considered standardized if they contain 24% ginkgo flavonoid glycosides and 6% terpene lactones.
Treatment should continue for at least 6 to 8 weeks, but therapy beyond 3 months isn't recommended.
Monitor patient for possible adverse reactions, such as GI problems, headaches, dizziness, allergic reactions, and serious bleeding.
Toxicity may cause atonia and adynamia.
Advise patient who plans to take gingko for motion sickness to begin taking it 1 to 2 days before beginning the trip and to continue taking it for the duration of his trip.
Inform patient that the therapeutic and toxic components of ginkgo can vary significantly from product to product. Advise him to obtain ginkgo from a reliable source.
Advise patient to keep herb out of reach of children.
Advise patient to discontinue use at least 2 weeks before surgery.
Tell patient to notify pharmacist of any herbal or dietary supplement that he's taking when obtaining a new prescription.
Advise patient to consult his a health care provider before using an herbal preparation because a conventional treatment with proven efficacy may be available.
Seizures have been reported in children after ingestion of more than 50 ginkgo seeds.
Both oral and intravenous forms of gingko are available in Europe, where it is one of the most widely prescribed medications. Neither form has been approved for medical use in the United States, although ginkgo is sold as a nutritional supplement.
An extract of the leaves has been shown to have pharmacologic activity in the patients with cerebral insufficiency, dementias, circulatory disorders, and bronchoconstriction. The plant is also known for its antioxidant and neuroprotective effects. Ginkgo extract has not been linked with severe adverse effects, but contact with the fleshy fruit pulp can cause allergic dermatitis, similar to the effect of poison ivy. Limited human data is available on teratogenicity.