Medicines Q&As
Q&A 91.3
Can a person on low dose aspirin take ginkgo?
Prepared by UK Medicines Information (UKMi) pharmacists for NHS healthcare professionals
Date prepared: 18th July 2012
Background
Ginkgo has a long history of medicinal use. Standardised concentrated extracts of Ginkgo biloba
leaves are marketed in several European countries (1). Ginkgo is mainly used in patients with poor
memory and poor cognitive function due to cerebral insufficiency (2). It is also used in intermittent
claudication (generally resulting from peripheral arterial occlusive disease), and vertigo and tinnitus of
vascular origin (1). Patients with these conditions who choose to self-medicate with ginkgo may often
already be taking low-dose aspirin for thromboprophylaxis.
Answer
Available data indicate that standardised extracts of ginkgo leaf are well tolerated when used at
recommended doses (1). There are few reports of serious toxicity. Headache, nausea, vomiting,
heartburn and diarrhoea have been reported occasionally. There have been rare reports of severe
allergic reactions, including skin reactions (e.g. itching, erythema and blisters) and convulsions (2).
Pharmacodynamic studies suggest that ginkgo inhibits platelet aggregation and several case reports
have documented serious bleeding events in patients taking ginkgo (1,3).
A systematic review identified 15 published case reports describing an association between using
ginkgo and a bleeding event (4). Most of the events were serious including 8 episodes of intracranial
bleeding. Of these, two patients required surgical evacuation, two patients were left with permanent
neurologic defects, and one patient died. Four cases involved ocular bleeding. Of these, all returned
to baseline vision, although one required surgical intervention. Where stated, the duration of ginkgo
exposure before onset of the adverse event varied from less than two weeks' exposure for the two
cases of spontaneous hyphema, less than two months' exposure for two cases of intracranial
bleeding, and more than six months' exposure for eight other cases. In 13 of the 15 reports there were
clinical risk factors such as age and/or the concurrent use of other medicines known to increase the
risk of bleeding. Two case reports involved aspirin. There was one report of spontaneous hyphema
following the addition of ginkgo in a patient taking aspirin 325mg daily. In another report, a patient with
liver cirrhosis taking 81mg aspirin daily developed peri-hepatic haematomas and a vitreous
haemorrhage (4,5). Only 6 of the 15 reports clearly described that ginkgo was stopped and that
bleeding did not recur. Bleeding time was measured in three cases, and was increased whilst patients
were taking ginkgo (4). A second review challenges the role of ginkgo biloba in these adverse events.
However the paper includes a statement of a conflict of interest due to the author’s involvement with
companies promoting this product (6). Two further systematic reviews conclude that the evidence
from a limited number of studies does not confirm that ginkgo biloba has a significant effect on blood
coagulation parameters. A small number of studies on concomitant use of ginkgo biloba with aspirin
or warfarin did not suggest that ginkgo has an additive effect to the clinical effects of these two drugs
(7,8). Further studies are needed to assess the effects of ginkgo biloba on a variety of blood
coagulation parameters (7).
Ginkgo should not be used in patients with previous or existing bleeding disorders unless the potential
benefits outweigh the potential harms (1). In view of the lack of conclusive evidence for the efficacy of
ginkgo leaf in the various conditions for which it is used, and the serious nature of the potential harm,
it is extremely unlikely that the benefit-harm balance would be in favour of such patients using ginkgo
(1).In view of the risks associated with this product, patients should be advised not to use ginkgo
without medical supervision (2).
From the NHS Evidence website www.evidence.nhs.uk
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Medicines Q&As
Aspirin has antiplatelet, analgesic, antipyretic and anti-inflammatory properties (9). The usual dosage
for long-term use, for the secondary prevention of thrombotic cerebrovascular or cardiovascular
disease and following by-pass surgery, is 75mg - 150mg once daily (10).
It is advised that ginkgo should be avoided or used cautiously in patients who are taking antiplatelet or
anticoagulant drugs (1,2,3,5,11). Whilst evidence is still not entirely conclusive and some may find this
approach overcautious, care should be taken with combinations of agents that inhibit platelet function.
This approach seems reasonable until further data are available.
Summary
 Pharmacodynamic studies suggest that ginkgo inhibits platelet aggregation.
 Spontaneous bleeding has been reported with the use of ginkgo alone.
 There may therefore be an increased risk of bleeding if ginkgo is combined with antiplatelet or
anticoagulant drugs.
 A small number of studies have not shown that ginkgo biloba has an additive effect to the clinical
effects of aspirin.
 There are, however, case reports of bleeding in patients taking ginkgo together with antiplatelet
drugs.
 Ginkgo should be avoided or used cautiously in patients who are taking antiplatelet drugs such as
low dose aspirin.
 Patients should be advised not to use ginkgo without medical supervision.
Limitations
Interactions between ginkgo and drugs other than aspirin are not specifically reviewed in this Q&A.
Disclaimer
 Medicines Q&As are intended for healthcare professionals and reflect UK practice.
 Each Q&A relates only to the clinical scenario described.
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References
1. Barnes J, Anderson LA, Phillipson JD, Herbal Medicines. Pharmaceutical Press. Electronic
version. Accessed via http://www.medicinescomplete.com 4 July 2012
2. Mason P. Ginkgo biloba. Dietary Supplements 4th ed. Pharmaceutical Press 2012 p222-228
3. Anon. Ginkgo. Natural Medicines Comprehensive Database. Accessed via
www.naturaldatabase.com 4 July 2012
4. Bent S et al. Spontaneous bleeding associated with Ginkgo biloba. A case report and
systematic review of the literature. J Gen Intern Med 2005; 20: 657–661
5. DRUGDEX® Drug – aspirin. MICROMEDEX(R) 2.0 Healthcare Series. Accessed via
http://www.thomsonhc.com - 3 July 2012
6. Bone KM. Potential interaction of Ginkgo biloba leaf with antiplatelet or anticoagulant drugs:
What is the evidence? Mol.Nutr.Food Res 2008;52:764-771
7. Savovic J, Wider W, Ernst E. Effects of ginkgo biloba on blood coagulation parameters: A
systematic review of randomised clinical trials. Evidence-Based Integrative Medicine
2005:2(3):167-176
From the NHS Evidence website www.evidence.nhs.uk
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Medicines Q&As
8. Izzo AA, Ernst E. Interactions between herbal medicines and prescribed drugs. An updated
systematic review. Drugs 2009;69(13)1777-1798
9. Martin J, editor. British National Formulary No 63.London: British Medical Association and the
Royal Pharmaceutical Society of Great Britain; March 2012. Electronic version. Aspirin.
Accessed via www.bnf.org on 4 July 2012
10. Intrapharm. Summary of Product Characteristics – Aspirin tablets BP 75mg. Accessed via
www.medicines.org.uk/EMC/default.aspx on 18 July 2012 [date of revision of the text 13
February 2012].
11. Williamson E, Driver S, Baxter K, editors. Stockley’s Herbal Medicines Interactions. The
Pharmaceutical Press; Accessed via http://www.medicinescomplete.com 4 July 2012 [Ginkgo
+ antiplatelet drugs monograph revised 20 September 2010]
Quality Assurance
Prepared by
Gill Lewis, South West Medicines Information & Training, Bristol Royal Infirmary, Marlborough Street,
Bristol BS2 8HW
Date Prepared
18th July 2012
Checked by
Julia Kuczynska, South West Medicines Information & Training, Bristol Royal Infirmary, Marlborough
Street, Bristol BS2 8HW
Date of check
7th August 2012
Search strategy
 Embase: ACETYLSALICYLIC ACID/IT + GINKGO BILOBA (limit to Publication Year 2010Current)
 Medline: ASPIRIN + GINKGO BILOBA
 Micromedex 2.0 Monograph for Aspirin Accessed 3/7/2012
 Natural Medicines Comprehensive Database. Monograph for Ginkgo. Accessed 4/7/2012
 In-house database/resources
 NeLM ASPIRIN + GINKGO Accessed 4/7/2012
From the NHS Evidence website www.evidence.nhs.uk
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