Usage
- Ginkgo biloba is primarily used to improve cognitive function, particularly in cases of dementia, Alzheimer’s disease, and age-related memory decline. It’s also prescribed for conditions affecting blood circulation, such as intermittent claudication (leg pain due to poor circulation), vertigo, tinnitus, and Raynaud’s phenomenon. Some studies also suggest its use in premenstrual syndrome, SSRI-induced sexual dysfunction, and normal tension glaucoma.
- Pharmacological classification: Ginkgo biloba is classified as a herbal supplement, nootropic (cognitive enhancer), and vasodilator.
- Mechanism of action: Ginkgo biloba is believed to work through multiple mechanisms, including improving blood flow by dilating blood vessels, acting as an antioxidant, reducing platelet aggregation (blood clotting), and modulating neurotransmitter systems.
Alternate Names
- Maidenhair tree, kew tree, Japanese silver apricot.
- Brand names: Tebonin, Ginkgold, Tanakan.
How It Works
- Pharmacodynamics: Ginkgo biloba improves blood circulation throughout the body, including the brain, enhancing oxygen and nutrient delivery. Its antioxidant properties protect cells from damage by free radicals. It also influences neurotransmitter systems, potentially improving cognitive function.
- Pharmacokinetics: Ginkgolides, the active components, are absorbed orally, metabolized in the liver, and eliminated mainly through the kidneys. The half-life is about 4-6 hours.
- Mode of action: Ginkgo biloba’s components, primarily flavonoids and terpenoids, dilate blood vessels, scavenge free radicals, and modulate neurotransmitter activity. It has been proposed that ginkgolide B, a terpenoid, is a potent platelet-activating factor (PAF) antagonist, which can explain some of the effects of ginkgo.
- Elimination pathways: Primarily renal excretion, with some hepatic metabolism.
Dosage
Standard Dosage
Adults:
- 120-240 mg of standardized extract (EGb 761) daily, divided into two or three doses. The extract should be standardized to contain 24% ginkgo flavone glycosides and 6% terpene lactones.
Children:
- Not generally recommended for children under 12. Limited evidence suggests 60-120 mg twice daily might be used in ADHD under strict medical supervision. Pediatric safety is not fully established.
Special Cases:
- Elderly Patients: No specific dosage adjustments, but start with a lower dose and monitor closely.
- Patients with Renal Impairment: Caution advised; dose adjustment may be necessary.
- Patients with Hepatic Dysfunction: Caution advised; dose adjustment may be necessary.
- Patients with Comorbid Conditions: Exercise caution in patients with bleeding disorders, diabetes, or those taking anticoagulants or anticonvulsants. Monitor closely for drug interactions.
Clinical Use Cases
- Intubation: No specific dosage recommendations.
- Surgical Procedures: Discontinue ginkgo at least two weeks before surgery due to bleeding risk.
- Mechanical Ventilation: No specific dosage recommendations.
- Intensive Care Unit (ICU) Use: No specific dosage recommendations.
- Emergency Situations: No specific dosage recommendations for emergency use.
Dosage Adjustments
- Dose adjustments may be required based on renal or hepatic impairment, concomitant medications, and individual response.
Side Effects
Common Side Effects
- Headache, dizziness, nausea, gastrointestinal upset, allergic skin reactions, constipation.
Rare but Serious Side Effects
- Bleeding, seizures (especially with high doses or seed ingestion), allergic reactions.
Long-Term Effects
- Limited data on long-term effects; some concerns about potential increased cancer risk in rodents require further research.
Adverse Drug Reactions (ADR)
- Bleeding, allergic reactions, seizures.
Contraindications
- Hypersensitivity to ginkgo.
- Bleeding disorders.
- Epilepsy or seizure disorders.
- Pregnancy and breastfeeding (safety not established).
- Concomitant use with certain medications (e.g., anticoagulants, anticonvulsants).
Drug Interactions
- Anticoagulants/antiplatelet drugs (e.g., warfarin, aspirin): Increased bleeding risk.
- Anticonvulsants: Potential reduced efficacy of anticonvulsants, increased seizure risk with high doses of ginkgo.
- Antidepressants (e.g., fluoxetine, imipramine): Potential reduced efficacy of antidepressants.
- Statins (e.g., simvastatin, atorvastatin): Potential reduced efficacy of statins.
- Diabetes medications: May alter blood sugar control.
- NSAIDs (e.g., ibuprofen): Increased bleeding risk.
- Alprazolam: Reduced efficacy of alprazolam.
- Nifedipine: Reported interaction with potential blood pressure effects.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: Not established. Ginkgo is generally considered unsafe during pregnancy and should be avoided due to potential bleeding risk and possible adverse effects on fetal development.
- Breastfeeding: Ginkgo’s safety during breastfeeding is unknown; it’s best to avoid it due to potential neonatal exposure.
Drug Profile Summary
- Mechanism of Action: Enhances blood flow, antioxidant, anti-platelet, neurotransmitter modulation.
- Side Effects: Headache, dizziness, GI upset, bleeding, allergic reactions, seizures.
- Contraindications: Hypersensitivity, bleeding disorders, epilepsy, pregnancy, breastfeeding.
- Drug Interactions: Anticoagulants, anticonvulsants, antidepressants, statins, diabetes medications, NSAIDs, alprazolam, nifedipine.
- Pregnancy & Breastfeeding: Avoid.
- Dosage: 120-240 mg/day divided BID-TID (adults).
- Monitoring Parameters: Cognitive function, blood pressure, bleeding signs, blood sugar (in diabetics).
Popular Combinations
- No established popular combinations.
Precautions
- General Precautions: Assess bleeding risk, monitor for drug interactions, discontinue before surgery.
- Specific Populations: Avoid in pregnancy/breastfeeding, caution in children/elderly, and those with bleeding disorders, epilepsy, diabetes.
- Lifestyle Considerations: Avoid alcohol, monitor blood sugar if diabetic.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Ginkgo Biloba?
A: 120-240 mg of standardized extract (EGb 761) daily, divided into two or three doses, for adults. Not recommended for children under 12.
Q2: What are the primary uses of Ginkgo Biloba?
A: Cognitive enhancement (dementia, memory decline), circulatory disorders (intermittent claudication, vertigo, tinnitus, Raynaud’s phenomenon).
Q3: What are the common side effects of Ginkgo Biloba?
A: Headache, dizziness, nausea, gastrointestinal upset, allergic skin reactions, constipation.
Q4: What are the serious side effects of Ginkgo Biloba?
A: Bleeding, seizures (especially with high doses or seed ingestion), allergic reactions.
Q5: Can Ginkgo Biloba be used during pregnancy or breastfeeding?
A: No, it’s considered unsafe during pregnancy and breastfeeding due to potential risks.
Q6: Does Ginkgo Biloba interact with other medications?
A: Yes, it can interact with anticoagulants, anticonvulsants, antidepressants, statins, diabetes medications, NSAIDs, and others. Consult a healthcare professional before combining ginkgo with other medications.
Q7: Who should not take Ginkgo Biloba?
A: People with bleeding disorders, epilepsy, or hypersensitivity to ginkgo. Pregnant and breastfeeding women should also avoid it.
Q8: How long does it take for Ginkgo Biloba to work?
A: It may take several weeks (up to 8 weeks) of consistent use to notice any effects.
Q9: Are there any dietary restrictions when taking Ginkgo Biloba?
A: No specific dietary restrictions, but be cautious with alcohol due to potential increased bleeding risk. Monitor blood sugar carefully if diabetic.
Q10: What should I do if I experience side effects while taking Ginkgo Biloba?
A: Stop taking the supplement and consult a healthcare professional, especially if the side effects are severe or persistent.
