By Lilian Anekwe
GPs are being urged to use the lowest possible dose of statins because of the risk of adverse events associated with the drugs revealed in a BMJ study published today.
A primary care study by researchers at the University of Nottingham found the type, dose and duration of statins increase the risk of adverse effects by different degrees.
They studied data drawn from 368 general practices in the QResearch database, which provided the records of two million new statin users aged 30-84 years including 225,922 patients who were prescribed simvastatin, atorvastatin, fluvastatin, pravastatin and rosuvastatin.
The patients’ adverse outcomes were recorded over eight years from January 2002 to June 2008.
The researchers estimated the effects of type, dose and duration of statin use and then calculated the numbers needed to treat and harm.
Statin use was associated with increased risks of moderate or serious liver dysfunction, acute renal failure, moderate or serious myopathy and cataracts.
For every 10,000 high-risk women treated with statins, there would be approximately 271 fewer cases of cardiovascular disease, eight fewer cases of oesophageal cancer; 74 extra patients who experience liver dysfunction; 23 extra patients with acute renal failure, 307 extra patients with cataracts, 39 extra patients with myopathy.
Similar figures were found for men except rates of myopathy were higher.
Adverse effects were similar across all statin types except liver dysfunction, where the risk was highest in patients prescribed fluvastatin.
The adjusted hazard ratio for fluvastatin was 3.08 at doses of 20mg and higher compared with 1.64 for lower doses.
A second analysis validates individual patient algorithms that GPs can use to explain absolute and relative risks and benefits to patients, as well as identify those at high risk of adverse events from statins and monitor them.
Professor Julia Hippisley-Cox, professor of clinical practice and epidemiology and a GP in Nottingham, concluded in the BMJ: ‘Our study may be useful for informing guidelines on the type and dose of statins. The findings would tend to support a policy of using lower doses of statins in people at high risk of adverse events.’
Different statins have different adverse event risks