title: Effect of Ginkgo biloba (EGb 761) and aspirin on platelet aggregation and platelet function analysis among older adults at risk of cardiovascular disease: a randomized clinical trial.
abstract: Several case reports have implicated Ginkgo biloba in clinically adverse bleeding disorders. Ginkgo biloba has been reported to increase pain-free walking distance among patients with peripheral artery disease (PAD). Standard PAD therapy includes 325 mg/day aspirin. The objective of this study was to examine potential adverse effects of concomitant aspirin and Ginkgo biloba on platelet function. Ginkgo biloba (EGb 761, 300 mg/day) was compared with placebo for effects on measures of platelet aggregation among adults consuming 325 mg/day aspirin in a randomized, double-blind, placebo-controlled, parallel design trial of 4-week duration. Participants were adults, age 69 +/- 10 years, with PAD or risk factors for cardiovascular disease. Outcome measures included platelet function analysis (PFA-100 analyzer) using ADP as an agonist (n = 26 placebo; n = 29 ginkgo), and platelet aggregation using ADP, epinephrine, collagen and ristocetin as agonists (n = 21 placebo; n = 23 ginkgo). Participants kept daily logs of bleeding or bruising episodes. There were no clinically or statistically significant differences between treatment groups for any agonists, for either PFA-100 analysis or platelet aggregation. Reports of bleeding or bruising were infrequent and similar for both study groups. In conclusion, in older adults with PAD or cardiovascular disease risk, a relatively high dose of Ginkgo biloba combined with 325 mg/day daily aspirin did not have a clinically or statistically detectable impact on indices of coagulation examined over 4 weeks, compared with the effect of aspirin alone. No adverse bleeding events were observed, although the trial was limited to a small sample size.
authors.affiliation: Stanford Prevention Research Center and the Department of Medicine, Stanford University Medical School, Stanford, California, USA. cgardner@stanford.edu
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Gardner
authors.forename: James L
authors.initials: JL
authors.lastname: Zehnder
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Rigby
authors.forename: Joel R
authors.initials: JR
authors.lastname: Nicholus
authors.forename: John W
authors.initials: JW
authors.lastname: Farquhar
mesh_terms: D000368:Aged; D001241:Aspirin / Q000494:pharmacology* / Q000627:therapeutic use; D001792:Blood Platelets / Q000187:drug effects; D002317:Cardiovascular Agents / Q000494:pharmacology* / Q000627:therapeutic use; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D020441:Ginkgo biloba; D006801:Humans; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000188:drug therapy*; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D010979:Platelet Function Tests / Q000379:methods; D000096983:Ginkgo Extract
chemical_list: D001241:Aspirin; D002317:Cardiovascular Agents; D010936:Plant Extracts; D010975:Platelet Aggregation Inhibitors; C063170:Ginkgo biloba extract; D000096983:Ginkgo Extract