Statins and their effect on cognition: Let's clear up the confusion.

Abstract

Lipid-lowering drugs, such as statins, rank in the top 5 most frequently used prescription drugs in Canada. In fact, between 2007 and 2011, more than 2.9 million Canadians were taking a lipid-lowering drug.1 With a plethora of robust evidence for secondary prevention of cardiovascular disease, coupled with a well-tolerated adverse effect profile, it is no wonder that statins are prescribed quite often. In the past decade, however, some case reports have suggested a possible increase in the risk of cognitive adverse events, such as memory loss, forgetfulness or feeling “fuzzy,” associated with their use.2 In 2005, Health Canada released a statement in the Canadian Adverse Reaction Newsletter suggesting a possible association between statins and memory loss.3 The onset of these adverse events described in the case reports varied, but most occurred within 1 year of statin initiation. Most of the cases (11/19) reported an improvement in cognitive symptoms once the statin was stopped or the dose reduced. In 2012, the Food and Drug Administration (FDA) issued a safety announcement to health care professionals, warning them about the potential risk of cognitive impairment (memory loss, forgetfulness, amnesia, memory impairment, confusion) with the use of statins for a period of 1 day to years.2 Review of these cases did not reveal an association between cognitive impairment and a specific statin, dose or age of patient. These cases were generally reversible, with symptoms disappearing approximately 3 weeks after statin discontinuation. The FDA also enforced a change in the monograph of statin products to warn health care professionals about this rare, but possible, adverse event. This change in monograph has not been mandated in Canada. On the opposite end of the spectrum, some research evaluated the potential use of statins in the prevention and treatment of Alzheimer disease (AD).4 This article focuses on the effects of statins on cognition and the use of statins for the prevention and treatment of AD.