I have had two patients with memory issues report to me that other doctors have suggested they should consider stopping
their simvastatin and see if this helps with their memory. What is the evidence for the effects of simvastatin on memory/cognitive
Memory loss is a rarely reported adverse effect of statins, without proven causality. Several cases of memory loss
have been reported to various adverse drug reaction databases, some of which were confirmed by re-challenge with the
The proposed mechanism for memory loss relates to the essential role of cholesterol in myelin production. Statins,
especially atorvastatin and simvastatin which are more lipophilic, may cross the blood-brain barrier and decrease the
amount of central nervous system cholesterol necessary for the formation of myelin. Inadequate myelin production may
result in demyelination of nerve fibres in the central nervous system and thus lead to memory loss.2
Memory impairment is common among people in the older age group and can be due to a variety of causes or conditions,
often multifactorial. It may be difficult to precisely determine whether a statin is implicated in a case of memory
If a patient experiences memory loss (or any other adverse effect) while taking a statin, the following approach could
- Stop the statin, observe whether symptoms improve, then re-challenge
- Lower the dose
- Switch to a different type of statin
- If symptoms persist, consider other lipid lowering treatments e.g. nicotinic acid or bezafibrate
There have also been rare reports of impairment of cognitive function with statins, however the evidence is conflicting
and inconclusive. While some studies have observed a mild detrimental effect of statins on cognition, others have shown
a beneficial effect. In a recent population-based study, there was no significant difference in cognitive performance
between elderly participants treated with statins and those who were untreated (controls).3 There are, however,
isolated case reports that raise the possibility that statins, in rare cases, may be associated with cognitive impairment.4
- Sweetman SC. Martindale: The complete drug reference. 36th edition. Pharmaceutical Press, London, March 2009.
- Trottier M. Statins and memory loss. Can Adverse React News 2005; 15 (4): 2.
- Benito-León J, Louis ED, Vega S, Bermejo-Pareja F. Statins and cognitive functioning in the elderly: a population-based
study. J Alzheimers Dis. 2010 Jan;21(1):95-102.
- Wagstaff LR, Mitton MW, Arvik BM, Doraiswamy PM. Statin-associated memory loss: analysis of 60 case reports and
review of the literature. Pharmacotherapy. 2003 Jul;23(7):871-80.