Gingko Leaf, cautions
- Side effects from using unstandardized ginkgo leaves are rare. However, large amounts or concentrations have been reported to cause gastrointestinal disturbance, irritability, restlessness, and headache
- As a general rule it is best to consult your health professional before taking this herb.
- Ginkgo leaf can negatively affect the blood’s ability to clot, so avoid ginkgo for at least a week before surgery
- Ginkgo is known to inhibit platelet activation factor and for this reason it is advisable to use caution when combining ginkgo with warfarin, heparin, aspirin or any other drugs with anticoagulant or antiplatelet effects. One case report suggests a probable interaction between ginkgo and aspirin.
- may increase the action of MAOIs if taken concurrently (theoretical).
- may decrease the anticonvulsant effect of anticonvulsants; avoid concurrent use.
- may interact with acetaminophen to increase the risk of bleeding.
- It is conceivable that ginkgo could interact with garlic, phosphatidylserine, policosanol and vitamin E.
- Prolonged use may cause mild side effects such as dizziness, headache, fatigue, gastric or chest discomfort, loss of appetite, constipation or diarrhea. The remedy belongs to the medium strength category because it has shown some cumulative toxicity and should not be used continuously on its own over a 2 or 3 month period.
- Fruit from the female trees may cause contact dermatitis or mouth lesions. Do not eat the pulp of the fruit. Even standing over roasting seeds can cause eye irritation and dermatitis.
- Avoid long-term use of the seed, and do not take more than ten seeds at a time. Excess use may cause fever, headache, irritation of the mucous membranes and skin, or emotional irritability.
- Prolonged bleeding time: Among some healthy volunteers in a pharmacodynamic study that evaluated the interaction of gingko with antiplatelet drugs .
- Seizures: In predisposed patients or those on medications that lowered the seizure threshold . Seizure associated with Ginkgo biloba? Contraindicated in patients with epilepsy due to lowering seizure threshold?
- Cutaneous reaction: Pruritus and macular erythema in a man after repeatedly ingesting a natural product containing ginkgo and vinpocetine . Fixed Drug Eruption to Supplement Containing Ginkgo biloba and Vinpocetine: A Case Report and Review of Related Cutaneous Side Effects.
- Acute hemolytic anemia (with injected ginkgo): In a patient with glucose-6- phosphate dehydrogenase (G6PD) deficiency receiving a G. biloba injection for dementia prophylaxis. Symptoms resolved following intravenous fluid infusion and discontinuation of G. biloba. Acute hemolytic anemia in glucose-6-phosphate dehydrogenase deficiency complicated by Ginkgo biloba.
Case reports
Spontaneous bleeding: Including hematomas , hyphema , and cerebral and intracerebral bleeding .
Spontaneous bilateral subdural hematomas associated with chronic Ginkgo biloba ingestion.
Spontaneous hyphema associated with ingestion of Ginkgo biloba extract
Association of Ginkgo biloba with intracerebral hemorrhage.
Ginkgo biloba and cerebral bleeding: a case report and critical review
Update on natural product—drug interactions
Review of Ginkgo biloba-induced toxicity, from experimental studies to human case reports.
Drug Interactions
Cytochrome P450 substrates: Studies show that ginkgo can inhibit and induce the CYP450 1A2, 2D6, and 3A4 enzymes but data are conflicting.
P-glycoprotein substrates: Ginkgo inhibits P-glycoprotein and can therefore interfere with drugs that are transported by P-glycoprotein .
UGT (Uridine 5’-diphospho-glucuronosyltransferase) substrates: Ginkgo modulates UGT enzymes in vitro and can increase the side effects of drugs metabolized by them.
MATE1 substrates: Isorhamnetin, a compound present in ginkgo was shown to be a strong inhibitor of the human multidrug and toxic compounds extrusion transporter 1 (hMATE1), responsible for the excretion of various drugs in the kidney and liver.
Anticoagulants / Antiplatelets: Ginkgo may induce or prolong bleeding time
Nonsteroidal anti-inflammatory drugs (NSAIDS): Ginkgo can have additive anticoagulant/antiplatelet effects.
Antipsychotics / Prochlorperazine: Ginkgo may cause seizures when combined with medications that lower the seizure threshold.
Insulin: Ginkgo can alter insulin secretion and affect blood glucose levels.
Trazodone: Ginkgo extract was associated with coma in a patient with Alzheimer’s disease who was also taking trazodone .
Efavirenz: Ginkgo may inhibit its effects .
Midazolam: Ginkgo may decrease serum concentrations .
Amlodipine: Ginkgo leaf tablet, a multiherbal formula containing ginkgo, was shown to inhibit the metabolism of amlodipine in a rat model
Effect of Schisandra chinensis extract and Ginkgo biloba extract on the pharmacokinetics of talinolol in healthy volunteers.
Interaction of Ginkgo biloba with efavirenz.
Association between priapism and concurrent use of risperidone and Ginkgo biloba.
Pharmacodynamic interaction studies of Ginkgo biloba with cilostazol and clopidogrel in healthy human subjects.
A potential drug-herbal interaction between Ginkgo biloba and efavirenz.
Effect of Ginkgo biloba extract on lopinavir, midazolam and fexofenadine pharmacokinetics in healthy subjects
Effect of Ginkgo Leaf Tablets on the Pharmacokinetics of Amlodipine in Rats