Statins do not cause the majority of the conditions that have been listed in their package leaflets, according to the most comprehensive review of side effects. The study was part-funded by us and published in The Lancet.
Cardiovascular disease causes around a quarter of all deaths in the UK. Statins are highly effective drugs that lower LDL (“bad”) cholesterol levels and have been proven to reduce the risk of cardiovascular disease. However, there have been concerns about possible side effects.
In an analysis of data from 23 large randomised double-blind studies, the researchers showed there is no excess risk from statin therapy for almost all the conditions listed in package leaflets as potential side effects.
The side effects investigated included memory loss or dementia, depression, sleep disturbance, erectile dysfunction, weight gain, nausea, fatigue or headache, and many other conditions.
There was a small increase in risk (about 0.1 per cent) for liver blood test abnormalities. However, there was no increase in liver disease such as hepatitis or liver failure, indicating that the liver blood test changes do not typically lead to more serious liver problems.
Countering misinformation
Professor Bryan Williams, our Chief Scientific and Medical Officer, said “These findings are hugely important and provide authoritative, evidence-based reassurance for patients. Statins are lifesaving drugs, which have been proven to protect against heart attacks and strokes. Among the large number of patients assessed in this well-conducted analysis, only four side effects out of 66 were found to have any association with taking statins, and only in a very small proportion of patients.
“This evidence is a much-needed counter to the misinformation around statins and should help prevent unnecessary deaths from cardiovascular disease. Recognising which side effects might genuinely be associated with statins is also important as it will help doctors make decisions about when to use alternative treatments.”
The researchers, led by a team at Oxford Population Health, assessed data from over 150,000 participants in 23 clinical trials – 19 trials involving 123,940 participants comparing the effects of statin therapies against a placebo (or dummy tablet), and four trials involving 30,724 participants which compared more intensive versus less intensive statin therapy.
They found similar numbers of reports for those taking the statins and those taking the placebo for almost all the conditions listed in package leaflets as possible side effects.
For example, each year, the number of reports of cognitive or memory impairment was 0.2 per cent in those taking the statins, but also 0.2 per cent in those taking the placebo. This means that while people may notice these problems whilst taking statins, there is no good evidence that they are caused by the statin.
“Our study provides reassurance”
Christina Reith, Associate Professor at Oxford Population Health and lead author of the study, said: “Statins are life-saving drugs used by hundreds of millions of people over the past 30 years. However, concerns about the safety of statins have deterred many people who are at risk of severe disability or death from a heart attack or stroke.
“Our study provides reassurance that, for most people, the risk of side effects is greatly outweighed by the benefits of statins.”
Previous work by the same researchers found that most muscle symptoms are not caused by statins. In the study, statin therapy caused muscle symptoms in only one per cent of people during the first year of treatment.
They have also shown that statins can cause a small increase in blood sugar levels, so people already at high risk may develop diabetes sooner.
Professor Sir Rory Collins, Emeritus Professor of Medicine and Epidemiology at Oxford Population Health and senior author of the paper said: “Statin product labels list certain adverse health outcomes as potential treatment-related effects based mainly on information from non-randomised studies which may be subject to bias.
“We brought together all of the information from large, randomised trials to assess the evidence reliably. Now that we know that statins do not cause the majority of side effects listed in package leaflets, statin information requires rapid revision to help patients and doctors make better-informed health decisions.”
Find out more about statins here