Statins not linked with most side effects in patient information leaflets

Statins do not cause most of the side effects listed in their package leaflets, including memory loss, depression, sleep disturbance, and erectile and sexual dysfunction, UK research has concluded.

A review of data from 23 large randomised controlled trials found similar numbers of reports for those taking the statins or those on placebo for almost all the conditions listed in package leaflets as possible adverse effects.

The analysis included 123,940 participants in 19 large-scale placebo-controlled trials and 30,724 participants in four trials comparing different statin doses.

Findings included that each year, the number of reports of cognitive or memory impairment was 0.2% in those taking the statins, but also 0.2% in those taking the placebo.

Previous research has shown that statin therapy can rarely lead to substantial muscle damage or, in a more severe form, rhabdomyolysis.

A study by the same team of researchers found that muscle symptoms while taking statins could only be attributed to the drugs in 1% of people during the first year of treatment.

Evidence has also been found of a moderate dose-dependent increase in new diagnoses of diabetes related to the use of statins, the majority occurring in individuals already close to the diagnostic threshold for diabetes when they start taking the drugs.

The latest study found of 66 further undesirable outcomes that had been attributed to statins only four were significant.

This included a small increase in risk (about 0.1%) for liver blood test abnormalities.

However, the team reported in The Lancet that there was no increase in liver disease such as hepatitis or liver failure.

Data from the four trials of more intensive versus less intensive statin regimens also found significant excesses for abnormal liver transaminases and other liver function test abnormalities that suggested a dose-dependent effect but no significant excess was found for urinary composition alteration or oedema.

Cardiovascular disease causes around a quarter of all deaths in the UK.

The evidence suggests that the undesirable effect sections of statin product labels might ‘overstate risks and mislead clinicians and patients’, they concluded.

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.’ 

Professor Bryan Williams, chief scientific and medical officer at the British Heart Foundation, said ‘These findings are hugely important and provide authoritative, evidence-based reassurance for patients.

‘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.’

He added: ‘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.’

Professor Kausik Ray, professor of public health at Imperial College London, said: ‘Warning labels often come from post marketing observations with no control arm. From a legal perspective, it makes sense but from a biological perspective it doesn’t.

‘The true test comes from blinded trials testing whether a treatment causes more harm than an inert comparator (placebo), when tested in double blind trials.’ 

He added: ‘These data are very important to provide reassurance and need to be widely disseminated as they are clinically relevant and actionable as theyprovide a reliable source of information for patients and help us with shared decision making.’

RCGP chair Professor Victoria Tzortziou Brown said: ‘Those considering taking statins should be reassured by this comprehensive study which shows that while statins, like any medication, have potential side effects, the risk for most people is low. 

‘It remains important to note that while statins can have real benefits for some patients, they won’t be appropriate for everyone so the decision to prescribe should always be the result of a conversation between the GP and patient about the various risks and benefits.’

She added it would be important to take into account this latest research as clinical guidelines are updated.