Ginkgo Biloba and Subarachnoid Hemorrhage

September 1998; Volume 1: 107

Source: Vale S. Subarachnoid hemorrhage associated with Ginkgo biloba. Lancet 1998;352:36.

Vale describes a 61-year-old man who presented with a five-day history of headache, back pain, nausea, and sleepiness. He had a normal blood count, mildly increased bleeding time (6 minutes; normal, 1-3), and normal prothrombin and partial thromboplastin times. A CT without infusion was normal. A lumbar puncture yielded 6 cc of xanthochromic fluid without gross blood. Microscopic examination revealed 6 cells per mcL, of which five were red and one was white. Glucose was 3.7 mmol/L; protein was 240 mg/L. A subarachnoid hemorrhage was diagnosed. Detailed questioning revealed that he had been taking Ginkgo biloba 40 mg tablets, three or four times a day, for more than six months before the beginning of his symptoms. The patient recovered uneventfully, was advised to stop the extract, and, in January 1998, was doing well. His bleeding time declined to 3 minutes; he refused further intervention.

COMMENT

This suggestive case report, submitted by a Mexican clinician, suggests a previously unreported associated effect of Ginkgo. Ginkgo's inhibition of platelet-activating factor is not as well known as it should be. Increased bleeding times, spontaneous hemorrhage, and subdural hematomas have been reported with chronic use.

The author suggests that those patients who take Ginkgo regularly and who have risk factors for intracerebral hemorrhage-tobacco dependence, hypertension, diabetes mellitus, and anticoagulant treatment including thrombolytic therapy-are at additional risk.

The incidence and prevalence of such complications is unknown but will likely become more apparent with clinician awareness.

Recommendation

Those patients on prescription anticoagulants and aspirin should be carefully monitored for signs or symptoms of exaggerated effects if they also take Ginkgo regularly.