The research, published in the BMJ and Heart, found that some statins can lead to an increased risk of liver dysfunction, acute renal failure, myopathy and cataracts in patients.
Researchers have recommended that the type and dosage of statin drugs should be proactively monitored and tailored to individual patients.
Cardiovascular disease is a leading cause of premature death and a major cause of disability in the UK. Statins are often recommended to reduce the risk of cardiovascular disease among high risk patients.
Julia Hippisley-Cox, professor of clinical epidemiology and general practice and Carol Coupland, associate professor in medical statistics at the University of Nottingham, wanted to measure the unintended effects of statins on certain clinical outcomes, taking into account the type, dose and duration of use.
They studied data from 368 general practices contributing to the QResearch database on 2,004,692 patients aged 30-84 years, who were prescribed a range of statins. They included 225,922 patients who were new statin users. The patients’ adverse outcomes were studied from January 2002 to June 2008.
The researchers estimated the effects of type, dose and duration of statin use on clinical outcomes that have been associated previously with statins and then calculated the numbers needed to treat and harm.
Their results, published in the BMJ, found no significant association between using individual statins and the risk of Parkinson’s disease, rheumatoid arthritis, venous thrombo-embolism, dementia, osteoporotic fracture, or many cancers including gastric, colon, lung, renal, breast or prostate. There was a reduced risk associated with statin use for oesophageal cancer.
There was, however, an increased risk associated with using statins for moderate or serious liver dysfunction, acute renal failure, moderate to serious myopathy and cataracts and evidence of a dose response for acute renal failure and liver dysfunction; higher doses were associated with greater risk.
Adverse effects were similar for all of the statins except for liver dysfunction, where the highest risks were with fluvastatin. All of the increased risks persisted during treatment, but were highest in the first year.
A companion paper by the same researchers in Heart shows that QResearch’s newly-developed and validated risk prediction algorithms could be used to identify patients at high risk of adverse events from statins so that they could be monitored more closely.
Julia Hippisley-Cox, lead author of both studies said “These studies are likely to be useful at national level for policy and planning. They can help inform guidelines on the type and dose of statins. For an individual patient, however, the important thing is to balance the risks and benefits of statins given their characteristics, so the patient can make an informed choice. For the vast majority of patients at high risk of heart disease the benefits from statins will outweigh the risks but a small number of people may be at risk of unintended effects. These studies help provide evidence and tools to better identify those at risk of unintended effects of statins so that they can be monitored more closely.”
The computer based risk calculator www.qintervention.org is designed primarily for use by clinicians but can also be used by patients. The software can also be integrated into GP clinical computer systems together with QRISK2 and QDScore, to alert doctors to patients who might be at risk of adverse events from statins and who might need closer monitoring.