Medicines Q&As
Q&A 303.2
Do statins cause amnesia?
Prepared by UK Medicines Information (UKMi) pharmacists for NHS healthcare professionals
Expiry: March 2014
Background
In November 2009, The Medicines and Healthcare Regulatory Agency published a Drug Safety
Update (2) which outlined changes to the product literature for the group of drugs known as the
statins (HMG Co-A Reductase Inhibitors: simvastatin, atorvastatin, pravastatin, fluvastatin and
rosuvastatin). The changes were to reflect updated information of adverse effects of the statins,
including listing memory loss as an adverse effect (2). The Food and Drug Administration (FDA) in the
US now also warns about memory loss potentially caused by statins (1)
This effect is believed to be due to the fact that cholesterol synthesis is essential for neuronal
function. As lipids account for about 50% of the dry matter in the central nervous system, cholesterol
is an essential component of myelin sheaths and synapses. This would suggest a possible
mechanism for memory loss (3).
Answer
Atorvastatin
Amnesia is listed as an uncommon adverse effect on the summary of product characteristics (SPC)
for atorvastatin (4). In one case report, a 68 year old female suffered memory loss which resolved
upon stopping atorvastatin. Subsequent re-challenge led to a return of symptoms which abated again
when the atorvastatin was stopped (5). In a further case report a 65 year old male on atorvastatin 10
mg/day for one year showed altered neuronal activity when taking atorvastatin. These symptoms
appeared to reverse upon discontinuation of atorvastatin (6).
Pravastatin
There are no case reports of pravastatin causing memory loss in the literature. Indeed, there is one
case report of a 51 year old male who suffered memory loss on simvastatin which resolved when
replaced with pravastatin. It has been suggested that this may be due to the fact that pravastatin is
less lipophillic than simvastatin (7), although the SPC for pravastatin does mention memory loss at
the request of the MHRA, as an adverse effect of other statins (8).
Simvastatin
In clinical trials the occurrence of memory loss in the simvastatin treatment group was similar to that in
the placebo group (9) (10) (11). There were 333 reports worldwide of memory loss obtained from the
manufacturer by the MHRA in which seven patients suffered positive re-challenge and three recorded
a positive de-challenge. 85 of the reports described resolution of symptoms on stopping simvastatin
and 25 reports indicating persistence of symptoms. The MHRA state that a causal relationship can
not be ruled out (12).
Fluvastatin
There are 40 medically confirmed post marketing cases of memory loss reported for fluvastatin, of
which 14 were serious and 26 were non serious. 14 of the reports also had other possible
explanations (11). Other explanations were that statins tend to be prescribed to older people, so there
could be other co morbidities such as dementia, Alzheimer’s disease and other forms of memory loss
that are more prevalent in an ageing population.
Rosuvastatin
Health Canada received four reports of memory loss associated with rosuvastatin, 2 of which had
positive de-challenge (13). In data provided to the MHRA by the manufacturer, the incidence rate was
3-0 per 1,000 patient years for rosuvastatin. There were no reports of memory loss in the placebo
group (11) and 41 post marketing case reports of memory loss that have been medically verified.
Time of onset is known in 16 of these reports and ranges from 2-210 days (11). Just over half of the
From the National Electronic Library for Medicines. www.nelm.nhs.uk
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Medicines Q&As
cases (56%) occurred within the first month of starting treatment. Among this group there where 10
reports of positive de-challenge (11). Memory loss is listed as a very rare adverse event in the SPC
for Crestor ® (rosuvastatin)(14).
Summary
There is limited supporting evidence of statins causing amnesia. Statins are widely prescribed- from
January 2011 to December 2011 there were 41,133,943 prescriptions for simvastatin (15).
Considering the relatively small number of case reports, it is likely that the incidence of memory loss
associated with statin therapy is low. The fact that statins are also often prescribed to older people
may also be a limiting factor as this population are more susceptible to memory loss as a normal sign
of aging or due to the presence of co-morbidities.
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Memory loss can be associated with many medical complaints.
As the process of memory involves lipids this is a potential mechanism for this adverse effect.
The more lipophillic statins appear to have the greatest potential to cause memory loss
although data is limited.
The balance of benefits from statin therapy still outweigh the risk of adverse effects
associated with these drugs.
Limitations
The information included in this Q&A was correct at the time of writing. Prescribing figures are from
England only.
Disclaimer
 Medicines Q&As are intended for healthcare professionals and reflect UK practice.

Each Q&A relates only to the clinical scenario described.

Q&As are believed to accurately reflect the medical literature at the time of writing.
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See NeLM for full disclaimer. 
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The authors of Medicines Q&As are not responsible for the content of external websites and
links are made available solely to indicate their potential usefulness to users of NeLM . You
must use your judgement to determine the accuracy and relevance of the information they
contain.
References
(1) FDA consumer update via
http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm293330.htm
(2) MHRA Drug Safety Update 2009 ; 3(4); 11
http://www.mhra.gov.uk/Publications/Safetyguidance/DrugSafetyUpdate/CON062553
(3) Tuccori M, Lapi F Testi A, et al. Statin-associated Psychiatric adverse events. Drug Safety
2008; 31(12): 1115-1125
(4) Summary of Product Characteristics-Lipitor (atorvastatin). Pfizer Ltd. Accessed via
http://www.emc.medicines.org.uk/medicine/1424/SPC/Lipitor+10mg%2c+20mg%2c+40mg%2c+
80mg+Tablets/ on 20th March 2011. [Date of revision of text 03/01/20012]
(5) King DS, Wilburn AJ, Wofford MR, et al. Cognitive impairment associated with atorvastatin
and simvastatin. Pharmacotherapy 2003; 23(12): 1663-1667
(6) Parker BA, Polk DM, Rabdiya V, et al Changes in memory function and neuronal activation
associated with atorvastatin therapy Pharmacotherapy 2010 vol 30 236-240
(7) Wagstaff LR, Mitton MW, Arvik BM, et al. Statin associated memory loss: Analysis of 60 case
reports and review of the literature. Pharmacotherapy 2003; 23(7): 871 – 880
(8) Summary of Product Characteristics- Lipostat (pravastatin). Bristol Meyers Squibb
Pharmaceuticals Ltd. Accessed via
From the National Electronic Library for Medicines. www.nelm.nhs.uk
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Medicines Q&As
http://www.emc.medicines.org.uk/medicine/1424/SPC/Lipitor+10mg%2c+20mg%2c+40mg%2c+
80mg+Tablets/ on 20th March 2012. [Date of revision of text 03/01/12]
(9) Pedersen TR, Berg K, Cook TJ, et al. Safety and tolerability of cholesterol lowering with
simvastatin during 5 years in the Scandinavian simvastatin survival study. Archives of internal
medicine 1996; 156: 2085 – 2092
(10)De Lemos JA, Blazing MA, Wiviott SD, et al. Early intensive vs delayed conservative
simvastatin strategy in patients with acute coronary syndromes: Phase Z of the A to Z trial. JAMA
2004; 292(11): 1307-7316
(11)MRC/BHF Heart protection study of cholesterol lowering with simvastatin in 20536 high-risk
individuals: a randomised placebo controlled trial. The Lancet 2002; 360: 7 – 22
(12)MHRA public assessment report statins: updates to product safety information November
2009
http://www.mhra.gov.uk/Safetyinformation/Safetywarningsalertsandrecalls/Safetywarningsandme
ssagesformedicines/CON062558
(13) Health Canada. Canadian Adverse reaction newsletter. 2005; 15(4): 2. http://www.hcsc.gc.ca/dhp-mps/alt_formats/hpfb-dgpsa/pdf/medeff/carn-bcei_v15n4-eng.pdf
(14) Summary of Product Characteristics- Crestor (rosuvastatin) Astra Zenica UL limited
accessed via
http://www.medicines.org.uk/EMC/medicine/11976/SPC/Crestor+5mg%2c+10mg%2c+20mg+an
d+40mg+film-coated+tablets/ accessed 20/03/12 (last updated 05/01/12)
(15) Personal communication with the Prescription Pricing Authority 16th March 2012.
Quality Assurance
Prepared by
Vincent J Cassidy, Regional Drug and Therapeutic Centre, Newcastle upon Tyne
Date Prepared
31st March 2010
Reviewed 20th March 2012
Checked by
Sonia Byers, Regional Drug and Therapeutics Centre, Newcastle upon Tyne
Update checked by Hayley Johnson. Regional Drug and Therapeutics Centre, Newcastle upon Tyne
Date of check
31st March 2010
Update: 26th March 2012
Search strategy
Embase (2010 -current)[Atorvastatin or Pravastatin or Simvastatin or Fluvastatin or
Rosuvastatin] + [amnesia or memory loss]
Medline (2010-current) [Atorvastatin or Pravastatin or Simvastatin or Fluvastatin or
Rosuvastatin] + [memory disorder
Pharmline [Atorvastatin or Pravastatin or Simvastatin or Fluvastatin or
Rosuvastatin] + [amnesia]
MHRA - Personal communication 9th February 2010
In house databases
Prescription Pricing Authority
From the National Electronic Library for Medicines. www.nelm.nhs.uk
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