Gingko is derived from the world’s most ancient tree that is native to China and Japan. Traditional Chinese herbal medicine recommends gingko as an antimicrobial, anti-inflammatory, and vasodilatory remedy. A concentrated standardized gingko biloba extract was developed in Germany in 1965, where it is available over the counter and by prescription. It is used in the US to enhance short-term memory, concentration, and alertness, particularly in the elderly. Earlier European and US studies indicated modest improvement in cognition of demented patients. A study last week in JAMA did not demonstrate any improvement in cognition in patients that took this herb.
The two main active components are flavonoids and terpenes. In-vitro studies indicate that the flavonoids possess free-radical scavenging activity, increase the duration of activity of endolthelium-derived relaxing factor, and promote cerebral vasodilatation. The terpenes antagonize platelet-activating factors.
Dermatitis is caused by contact with the seed and fruit pulp of gingko that contains products structurally related to urushiols found in poison ivy. Dermatitis should be treated with the same regimen as poison ivy. Eye exposure can result in conjunctivitis. Irrigation should occur immediately.
Ingestion of the seed produces seizures and coma in small children. This may be due to an antipyridoxine substance and pyridoxine has been administered in an attempt to reverse CNS effects. Ingestion of the fruit pulp causes GI irritant effects.
Ingestion of the extract is considered safe with rare reports of mild GI irritation, headache and allergic skin reactions. It has been implicated in bleeding events that occurred in patients on anticoagulants or platelet-inhibitors. Subdural hematomas has been reported in a patient that ingested this drug. ds
As always, if there are any questions, call the MTPC.
I am interested in any questions that you would like answered in “Question of the Week.” Please e-mail me with any suggestions at donna.seger@Vanderbilt.edu
Donna Seger, M.D.
Medical Director, Middle Tennessee Poison Center