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Why do patients have side effects with statins?

In the UK, as in other westernised nations, we have extremely high cholesterol levels. This is unnatural and is a key reason for the very high levels of heart attacks, strokes and other cardiovascular problems that we have in our society. The average cholesterol is about 5mmol/l in the UK compared with under 2mmol/l in societies that don’t have westernised lifestyles. That means that even the average person has about two and a half times as much fat in his or her blood vessels every second of every minute of every day of their adult lives. It’s not surprising our arteries get clogged up with fat.

Altering our diet can have some impact on the cholesterol levels but it’s often only a small impact. We do have medications though that are highly effective at lowering cholesterol, in particular statins. These drugs have been tested in the best type of clinical trials. These are called double blind, randomised controlled trials, where patients either get the drug or a dummy (placebo) tablet. Neither the patient, nor their doctor, know which they have been allocated (randomised to). Then someone independent, who has nothing to do with any of the patients’ medical care, counts up how many deaths, heart attacks, strokes and other events occur in patients taking the statin drug and how many in patients taking the placebo tablets. Our department at Imperial College London ran and published one of these trials, the ASCOT study, assessing statins in patients with high blood pressure. This study others have shown that for every 1mmol/l reduction in LDL cholesterol there is about a 20% reduction in deaths, heart attacks or strokes in patients taking statins. In view of this key information from these studies, many patients are advised to take statins to reduce their future risk of heart attack, strokes and death. 

However, many patients remain sceptical because there is a lot of information about potential problems with statins in the press and on the internet. Some patients don’t like taking tablets because it is unnatural. Sadly though, much of our westernised life is unnatural, from breathing in the polluted air in our cities, to eating processed food, to taking insufficient exercise. That’s without some of the other potentially more damaging lifestyle choices we may make. Perhaps adding a tablet to what we eat that rebalances some of the adverse effects of Westernisation isn’t so bad in comparison.

A lot of patients describe side effects when they take statins and that can be an important reason that patients don’t continue with them. However many of the potential side effects like muscle aches or indigestion are vague, and people who don’t take stains also commonly get these symptoms. Statins have attracted a lot of media interest, probably because so many people are taking them, and there is a lot of public information about what the side effects might be. Concern about these possible side effects does influence some patient’s decision about whether or not to take statins. 

Our research team at Imperial College London recently looked back at side effect data in our ASCOT statin study. During the study there was very little difference in side effects in the patient group taking the statin compared with the group taking the placebo (the dummy tablet) when the patients didn’t know what they were taking. When the study was over and patients were told what tablets they were taking the reported side effects from the patients taking statins was much higher than when they didn’t know they were taking the drug.

Another study that has recently been published from our department at Imperial College London used an interesting technique where patients were either given a statin, a dummy tablet or no tablet at all for a period of time. They then switched to the other tablet or to no tablet so they had some time in each group.  They reported their symptoms during the course of the study. The study suggested that most side effects attributed to statins are because patients expect to get the side effects (called the “nocebo effect”). This is the reverse of the “placebo effect” that you may have heard of where patient’s feel better with treatments because they expect to do so. 

It’s important that when any treatment is recommended, there is a careful explanation of the benefits of the treatment and also a discussion about possible complications, side effects and how side effects may occur, along with other possible causes of those symptoms. This is particularly important with statins because all of the different information and opinions available on the internet and elsewhere, make it very difficult for patients to make the best choice for them. Our role as cardiovascular experts is to help patients make informed choices about what they wish to do. 


Wood FA, Howard JP, Francis DP et al. New Engl J Med 2020. 


Posted on 04 January 2021
Author: Prof Jamil Mayet
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