Healthy Skepticism Library item: 2652

Warning: This library includes all items relevant to health product marketing that we are aware of regardless of quality. Often we do not agree with all or part of the contents.

 

Publication type: news

Gaffen A, Nesic M, Coleman G.
Statins and memory loss
Health Canada 2005 Oct 8
http://www.hc-sc.gc.ca/dhp-mps/medeff/bulletin/carn-bcei_v15n4_e.html

Notes:

Ralph Faggotter’s Comments:
Statins are widely used and abused.
I wonder how many people out there are on statins and suffering from varying degrees of statin-related memory loss without knowing why?

Full text:

Statins and memory loss

The role of HMG-CoA reductase inhibitors, or statins, in cardiovascular protection is well established. However, evidence in the current literature is conflicting as to the effect of statins on cognitive function.1 It has been postulated that statins may prevent dementia of the Alzheimer’s type through inhibition of β-amyloid formation and thus decreased production of neurofibrillary tangles and plaques.2 Other studies have suggested that statins can contribute to memory loss.1-4 The proposed mechanism relates to cholesterol’s essential role in myelin production. Statins, especially the more lipophilic ones (e.g., atorvastatin and simvastatin), may cross the blood-brain barrier and decrease the amount of central nervous system (CNS) cholesterol necessary for the formation of myelin.2,3 Inadequate myelin production may result in demyelination of nerve fibres in the CNS and thus lead to memory loss.2 Memory impairment is listed in the product monograph for Pravachol.5

From the date of marketing of statins in Canada to May 31, 2005, Health Canada received 19 reports of amnesia suspected of being associated with these drugs (Table 1). The onset was reported to occur within 1 month after starting statin therapy in 5 cases, within 1 year in 7 cases and after 1 year in 3 cases. Four cases did not report an onset date. Eleven reports described that the amnesia resolved or improved when the drug was discontinued or the dose reduced, and one of them also described a positive rechallenge. Other reports did not provide this information.

Given these findings, changes in cognitive status temporally associated with statin therapy should be monitored.2

Michel Trottier, BScPhm, RPEBC, RPh, Health Canada

References

1. Wagstaff LR, Mitton MW, Arvik BM, Doraiswamy PM. Statin-associated memory loss: analysis of 60 case reports and review of the literature. Pharmacotherapy 2003;23(7):871-80. 2. King DS, Wilburn AJ, Wofford MR, Harrell TK, Lindley BJ, Jones DW. Cognitive impairment associated with atorvastatin and simvastatin. Pharmacotherapy 2003;23(12):1663-7. 3. Orsi A, Sherman O, Woldeselassie Z. Simvastatin-associated memory loss. Pharmacotherapy 2001;21(6):767-9. 4. Muldoon MF, Ryan CM, Sereika SM, Flory JD, Manuck SB. Randomized trial of the effects of simvastatin on cognitive functioning in hypercholesterolemic adults. Am J Med 2004;117(11):823-9. 5. Pravachol (pravastatin) [product monograph]. Montréal: Bristol-Myers Squibb Canada; 2005.