Are statins safe? Only you and your doctor can decide

The controversy raging over the safety and effectiveness of statins is creating uncertainty among people taking them or who might need to consider doing so. Are statins as controversial as stories suggest?

Statins lower the amount of bad (low-density lipoprotein) cholesterol in your blood, and the higher your cholesterol, the greater the riskof a heart attack. If you have a gene defect that causes a very high cholesterol level – a condition called familial hypercholesterolaemia (FH) – then you are at very high risk of a heart attack. Before statins, doctors were virtually powerless to prevent such heart attacks because there were no drugs that were effective at reducing cholesterol without causing intolerable side effects. Statins changed all that.

Now people with FH can take a statin and expect to live a normal lifespan. Similarly, if you have suffered a heart attack, regardless of your cholesterol level, there is abundant uncontested evidence that taking a statin will reduce your risk of a further heart attack or stroke. So where is the problem?

The problem arises when we consider giving a statin to healthy people, who have no apparent cholesterol gene defect or evidence of heart disease, in the hope it will prevent a future heart attack. This is when doctors start to worry about the risk-to-benefit ratio. If a doctor is going to prescribe a statin for a healthy individual to protect against future heart disease, he or she wants to be pretty certain the drug won’t do more harm than good because, unfortunately, all drugs have side effects.

Statins reduce the risk of a heart attack or stroke even in those with relatively low cholesterol levels

So you and your doctor need to know three things – what are your chances of having a heart attack or stroke in the next few years without any treatment? How much would that risk be reduced if you took a statin? And what is the likelihood of a serious side effect?

By noting down some simple facts such as your age, gender, whether you smoke, your blood pressure, your cholesterol level and family history, your doctor can calculate your risk of suffering a heart attack or stroke in the next 10 years. Evidence on benefits and side effects comes from clinical trials designed to impartially quantify the benefits and risks of taking a statin.

The combined evidence from many such trials shows that statins reduce the risk of a heart attack or stroke even in those with relatively low cholesterol levels. But, because most people with low cholesterol levels are at relatively low risk of a heart attack, many people would need to be treated to prevent one of them from having a heart attack. This would not be a problem if there were no risks associated with taking a statin.

So what are the risks? Studies have identified three potentially serious but very rare risks. People taking statins are at slightly increased risk of developing type 2 diabetes. This seems to occur in people on the verge of developing it anyway, and despite the onset of diabetes those people are still at lower risk of heart attack or stroke in the future than they would be without a statin.

There is also a small increased risk of a haemorrhagic stroke – a bleed into the brain – but this risk is more than offset by the reduced risk of a stroke – caused by a blocked artery – if you take a statin, so your overall risk of a stroke is reduced.

The third risk is that statins can definitely cause a condition called myopathy which is characterised by muscle pain and evidence of muscle damage on blood tests. Very rarely, if the treatment is not stopped, this can progress to a potentially fatal condition called rhabdomyolysis. But if the treatment is stopped, the symptoms stop too. Patients are warned to watch out for muscle pains when they start taking a statin and, not surprisingly, many do complain of muscle pains. But few of them have actual myopathy. Placebo-controlled trials have shown that when patients are told to watch out for muscle pains, almost as many taking a placebo report experiencing them as do those taking the active drug. It is this phenomenon that has led to the perception that statin side-effects are common, which they are, but it does not mean they are unsafe.

So what should you do? If you are at high risk, take a statin. The risks of not taking one – a heart attack or a stroke – far outweigh risks associated with the drug. If you are not in this category, ask your GP to assess your risk then discuss the best way to reduce it. For many this will mean a change in lifestyle and diet, not a statin. If your doctor recommends a statin and you experience a side-effect, they can usually be resolved by reducing the dose or swapping to another brand.

Clinical trials tells us that, at a population level, statins are safe and effective. But only you and your doctor can decide if they are right for your needs. Be guided by your doctor rather than by what you might read or hear elsewhere.

Are statins safe? Only you and your doctor can decide