As a recent controversy over the safety of statins, the medication used by a quarter of a million Irish people, rumbles on, this week’s column will look at the evidence for the drug’s efficacy and safety.
Statins are a group of drugs used to lower a person’s cholesterol. They are used in conjunction with diet, exercise, smoking cessation and other non-pharmacological approaches to reduce the risk of heart attack and stroke.
Statins have been hugely successful in helping to achieve this goal, with many reputable scientific studies proving their efficacy. They are especially effective in preventing further heart attacks and strokes in patients who have already had one, so-called secondary prevention.
But there is also a multiplicity of evidence for the usefulness of statins in people who have been assessed as having a significantly higher risk of having heart disease in the future – for example, someone with a strong family history of heart attacks will benefit from their protective role.
For reasons of space I cannot list all of the studies showing the benefits of the medication but the independent and respected Cochrane Collaboration, in a major review of statins published last May, concluded that of 1,000 people treated with a statin over five years, 18 would avoid a major event such as a heart attack or stroke.
Controversy
The current controversy over the drugs seems to focus more on whether they are safe or not. I know that pharmacists and doctors around the country have been consulted by patients worried whether they should stop taking statins.
It follows widespread publicity of an article titled The Ugly Side of Statins, written by Mr Sharif Sultan and Dr Niamh Hynes of the Department of Vascular Surgery at NUI Galway, and published in the Open Journal of Endocrine and Metabolic Diseases.
The authors question the role of statins in the primary prevention of cardiovascular disease, while acknowledging their place in secondary prevention. But they express concern about possible side effects including the risk of cataracts, diabetes and dementia.
All drugs have side effects. The art of prescribing involves making a judgment whether the potential benefits outweigh the risks for the person sitting in front of you. And if minor side effects do occur, the patient must decide whether they will put up with the symptom in the interest of a long-term gain or to ask the doctor if there is an alternative.
Should a major side effect emerge as a risk with a particular drug, then in conjunction with advice from the Irish Medicines Board, the prescribing doctor may have to take patients off the offending medication.
Cataracts
Whether statins increase or decrease the risk of cataracts or not is something that has been see-sawing around the medical literature for some time.
The latest research, presented last month at the European Society of Cardiology congress, suggests statins reduce the risk of cataracts. At the conference, we also heard of research suggesting statin use was associated with a decreased incidence of dementia. Evidence is emerging that statins may cause a 10 per cent increase in the relative risk of developing diabetes. The finding may apply principally to people who are already at risk of diabetes in the future.
For those taking statins to prevent a future stroke or heart attack, in my opinion the risk benefit is still in favour of prescribing. But if you are in any doubt, ask your family doctor to assess the risks versus benefits for you.
I take a statin in order to prevent a future heart attack. I’ve had some niggling minor side effects but the drug has helped reduce my cholesterol levels significantly. I especially value its often under-rated anti-inflammatory effect, which means that any future blockages that develop in my coronary arteries are less likely to break off and cause an acute coronary event. Statins, along with aspirin, are life-saving drugs. It would be a mistake to stop them suddenly.
mhouston@irishtimes.com
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