Effects of Ginkgo biloba on Blood Coagulation Parameters

Abstract

A systematic literature review was conducted to investigate the effects of Ginkgo biloba preparations on blood coagulation parameters. Systematic literature searches were carried out using MEDLINE (via PubMed), EMBASE, AMED, CINAHL®, the Cochrane Library and PsycINFO to identify randomised, double-blind, clinical trials of G. biloba mono-preparations assessing at least one blood coagulation parameter as either a primary or a supplementary outcome measure. Five manufacturers of G. biloba preprations were asked to contribute any unpublished material. Data were validated and extracted independently by two reviewers according to pre-specified criteria. Eight trials were included, of which two included healthy subjects, four included patients with various conditions and two included participants taking concomitant anticoagulant medication, one with acetylsalicylic acid (ASA; aspirin) and one with warfarin. Overall results do not provide evidence that G. biloba does affect blood coagulation parameters in a clinically relevant manner. Out of many parameters assessed, four coagulation parameters from three studies were significantly different in the treatment group compared with the control. One study comparing the treatments of ASA and G. biloba with ASA alone confirmed that the two treatments were equivalent with regards to all but three coagulation parameters. Available evidence does not demonstrate that extract of G. biloba causes significant changes in blood coagulation parameters. A limited number of studies on concomitant use of G. biloba with ASA or warfarin also do not suggest that G. biloba has an additive effect to the clinical effects of these two drugs. Currently available evidence is limited and, therefore, further studies are needed to assess effects of G. biloba on a variety of blood coagulation parameters.