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KCE Reports 111 Interventions in Alzheimer’s Disease 35
Ginkgo biloba
Ginkgo biloba leaf extract is one of the most widely sold phytomedicines in Europe.
First, we had planned not to discuss Ginkgo biloba in this report as not robust data
were available. However, as a few reports covering Ginkgo were identified during the
course of this project we provide a brief summary here. The trials are weak from a
methodological point of view (patient population not well characterized, lack of power,
assessment of efficacy) and do not allow to make any firm conclusion. 10 Extract of
Ginkgo biloba can provide some relief of cognitive and Activities of Daily Living (ADL)
impairment (Evidence Grade 3). 14 Knowledge about long-term effects is limited to
therapy for six months. The recent IQWiG report (http://www.iqwig.de/ginkgo-bilobain-alzheimer-s-disease-evidence.818.en.html)
concludes that for the therapy goal
“activities of daily living”, there is evidence of a benefit of high-dose (240 mg daily)
Ginkgo extract EGb 761 in AD patients (but not for a lower dose or other extracts).
IQWiG reported the evidence was primarily based on 2 recent Ukrainian studies. 65
As results across studies are very heterogeneous; no summarizing conclusion can be
made on the potential effect size. In addition, there is an indication that this benefit is
only present in patients with accompanying psychopathological symptoms. 65 A recent
Cochrane review 66 concluded that the evidence that Ginkgo biloba has predictable and
clinically significant benefit for people with dementia or cognitive impairment is
inconsistent and unreliable. In addition, a recently published study did not show efficacy
for this drug in MCI patients. 67
In Belgium, Ginkgo biloba is reimbursed for the symptomatic treatment of mild to
moderately severe AD (MMSE > 11).
Other agents
Co-dergocrine or piracetam are not included in this evaluation because robust trial data
are lacking.
It must be stated that a number of molecules have shown promising results when
studied in AD patients. Some of the novel approaches to treating AD offer the potential
for disease modification. In addition to the approaches aiming to modify the amyloid
cascade or the protein aggregation, some molecules target the intraneuronal
accumulation of neurofibrillary tangles. Active or passive immunization trials, aiming at
various antigens, are also underway.
Guidance for the clinical development of medicinal products in Europe in the treatment
of Alzheimer’s Disease is available in a CPMP Note for Guidance
(http://www.emea.europa.eu/pdfs/human/ewp/055395en.pdf). Symptomatic
improvement after at least 6 months of treatment is to be demonstrated for the
cognition domain and either for activities of daily living or overall clinical response. An
update is in preparation for the development of possible disease modifying treatments.
Using the search strategy described above, we identified the following recent systematic
reviews of the published clinical trials.
Table 4. Systematic Reviews by Search Date
Reference Search date
Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen. Memantin bei December 2007
Alzheimer Demenz. Vorbericht A05-19C. Köln: IQWiG; 2008.
Raina P, Santaguida P, Ismaila A, Patterson C, Cowan D, Levine M, et al.
Effectiveness of cholinesterase inhibitors and memantine for treating dementia:
evidence review for a clinical practice guideline. Ann Intern Med.
2008;148(5):379-97.
Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen.
Cholinesterase inhibitors in Alzheimer's disease. Final report A05-19A. Köln:
IQWiG; 2007.
NICE-SCIE. Dementia: supporting people with dementia and their carers in
health and social care. Care guideline. National Institute for Health and Clinical
November 2006
June 2006
May 2006