A study conducted by researchers from Nottingham University in the UK has found that statins, which are prescribed to people with high levels cholesterol, may carry dangerous side effects including liver dysfunction and kidney failure.

The study, which was conducted on over two million people, showed increased risks of moderate or serious liver dysfunction, acute renal failure, moderate or serious myopathy and cataracts.

The increased risks were shown to persist during treatment, with the highest level of risk seen in the first year.

Stopping treatment resulted in the risk of cataracts returning to normal within a year in men and women. Risk of oesophageal cancer returned to normal within a year in women and within one to three years in men while the risk of acute renal failure returned to normal within one to three years in men and women, and liver dysfunction within one to three years in women and after three years in men.

The findings, published in the British Medical Journal, used data from 368 general practices from 2,004,692 patients aged 30-84 including 225,922 patients that were new statin users.

The authors said that the study would be useful for planning and policy purposes, but that further studies were needed to develop individual ways of diagnosing the risk to especially vulnerable patients.

A variety of cholesterol-lowering statins were used in the study, including fluvastatin, which is sold by Novartis under the brand names Lescol and Lochol.

Statins are among the most widely prescribed medicines and have been shown to be very effective against cardiovascular disease.