Unintended effects of statins explored
MedWire News: A study of hundreds of primary care practices in England and Wales has offered an insight into the unintended effects of statins.
Statins were not significantly associated with risk for Parkinson’s disease, rheumatoid arthritis, venous thromboembolism, dementia, osteoporotic fracture, or several common cancers.
The risk for esophageal cancer was reduced with statin treatment, but that for liver dysfunction, acute renal failure, myopathy, and cataract was increased. Adverse effects were similar across the statin types except for liver dysfunction, where fluvastatin was associated with the highest risk.
The findings, published in the British Medical Journal, come from 368 primary care practices with a total of 2,004,692 patients, aged 30 to 84 years.
Most of the 225,922 new statin users were prescribed simvastatin or atorvastatin, at 70.7% and 22.3%, respectively.
After stopping treatment, risk returned to normal within a year for cataracts in all patients and for esophageal cancer in women.
Risk returned to normal in 1 to 3 years for acute renal failure in both genders, and for esophageal cancer in men, and liver dysfunction in women. Liver dysfunction risk returned to normal from 3 years in men.
Based on the 20% threshold for cardiovascular risk, the number needed to treat (NNT) to prevent one case over 5 years in women was 37 for cardiovascular disease and 1266 for esophageal cancer. For men, the corresponding values were 33 and 1082.
The number needed to harm (NNH) in women for one additional case of acute renal failure over 5 years was 434. This figure was 259 for moderate or severe myopathy, 136 for moderate or severe liver dysfunction, and 33 for cataracts.
NNT and NNH values were similar in men, except for myopathy when NNH was 91.
Julia Hippisley-Cox and Carol Coupland (University Park, Nottingham, UK) say their study “is likely to be useful for policy and planning purposes.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
By Anita Wilkinson