Ginkgo Biloba

1. Indications (Purported benefits)
   1. Alzheimer's Disease
   2. Multiple-Infarct Dementia
   3. Used in Germany for:
      1. Intermittent Claudication
      2. Vertigo
      3. Tinnitus
2. Efficacy: Cognitive effects
   1. Preliminary studies suggest possible benefit
      1. Benefits likely to offer only modest effect
   2. Dementia Study, n=309, 120 mg qd for 1 year, RDBCT
      1. Ginkgo patients scored higher on cognitive tests
      2. Caregivers rated Ginkgo patients higher score
      3. Clinicians ratings found no difference
      4. Patients completing study: <50%
      5. Le Bars (1997) JAMA 278:1327 [PubMed]
   3. Van Dongen study found no benefit
      1. No benefit in Dementia
      2. No benefit in memory Impairment
      3. Van Dongen (2000) Am Geriatr Soc 48:1183-94 [PubMed]
   4. NIH DBPCT with n=2000 over 6 years is ongoing
      1. Sierpina (2003) Am Fam Physician 68(5):923-6 [PubMed]
3. Efficacy: Non-cognitive uses
   1. Peripheral Vascular Disease
      1. Study showed longer walking distance and less pain
      2. Peters (1998) Vasa 27:106-10 [PubMed]
   2. Tinnitus
      1. Modest effect on reduction or Tinnitus resolution
      2. Ernst (1999) Clin Otolaryngol 24:164-7 [PubMed]
4. Mechanism
   1. Components
      1. Flavonoids and Terpenoids are antioxidants
      2. Ginkgolide B (terpenoid)
         1. Inhibits Platelet activating factor
         2. Interferes with Platelet aggregation and blood clot
   2. Pharmacokinetics
      1. Readily absorbed
      2. Peak concentration in 2-3 hours after ingestion
      3. Excreted by Kidney, Liver
      4. Half life: 5 hours
5. Dosing
   1. Standardized extract: 120 to 160 mg divided bid to tid
   2. Standardized extract components
      1. Flavone glycosides: 24%
      2. Terpene lactones: 6%
6. Adverse Effects
   1. Mild Gastrointestinal symptoms (Vomiting, Diarrhea)
   2. Headache
   3. Serious bleeding complications (e.g. Subdural Hematoma)
      1. Associated with Aspirin and Warfarin use
      2. Due to Platelet Dysfunction
      3. Exacerbated by Garlic, Feverfew, Ginseng
   4. Seizures
      1. Reports of Seizures in those with Epilepsy and previously controlled on prophylaxis
7. Contraindications: Avoid use with Anticoagulants
   1. Aspirin
   2. Warfarin (Coumadin)
   3. Ticlopidine (Ticlid)
   4. Clopidogrel (Plavix)
   5. Dipyridamole (Persantine)
   6. Herbals with Anticoagulant activity
      1. Feverfew
      2. Garlic
      3. Ginseng
      4. Dong Quai
      5. Red Clover
8. Precautions
   1. Stop Ginkgo 36 hours to 14 days before surgery
9. References
   1. Shaughnessy (1997) Fam Practice Recert 19(10):53-6
   2. Ang-Lee (2001) JAMA 286:208-16 [PubMed]
   3. Cupp (1999) Am Fam Physician 59(5):1239-44 [PubMed]
   4. Sierpina (2003) Am Fam Physician 68(5):923-6 [PubMed]
   5. Zink (1998) Am Fam Physician 58(5):1133-40 [PubMed]