EGb 761 Does Not Affect Blood Coagulation and Bleeding Time in Patients with Probable Alzheimer's Dementia-Secondary Analysis of a Randomized, Double-Blind Placebo-Controlled Trial.

Following reports of bleeding upon Ginkgo intake, we assessed whether Ginkgo extract EGb 761 affects coagulation or platelet function or increases the risk of bleeding. In a double-blind, placebo-controlled trial, prothrombin time, activated partial thromboplastin time, international normalized ratio and bleeding time were measured in patients with Alzheimer's dementia at baseline, weeks 6 and 26. A total of 513 patients were randomized to 120 mg ( = 169) or 240 mg EGb 761 ( = 170) or placebo ( = 174). No relevant changes were found for coagulation parameters and bleeding time. Numbers of bleeding-related adverse events were similar in all groups. Concomitant intake of acetylsalicylic acid was documented for 68 patients in the placebo group and 105 in the EGb 761 groups. Within these groups, the means at baseline and week 26 differed by less than 1 unit for prothrombin time and bleeding time and less than 0.1 unit for international normalized ratio. Data on warfarin treatment in nine patients each taking placebo or EGb 761 did not indicate enhancement of warfarin effects by EGb 761. No evidence was found that EGb 761 affects hemostasis or increases the bleeding risk. No pharmacodynamic interactions with warfarin or acetylsalicylic acid were found.