Before taking a powerful prescription drug, the doctor - and patient - should weigh up the risks and benefits. Of course the doctor rarely does any such thing, and prescribes the drug as a matter of course.
Unfortunately no drug comes without side effects - and the drugs industry would argue that if one did, it wouldn't have any beneficial effects either. Take, for instance, the ACE (angiotensin-converting-enzyme) inhibitors, designed to reduce the risk of heart attack. Common side effects include low blood pressure, diarrhoea, cough, nausea and fatigue. More serious reactions can include angiodema, where vascular tissues fill with fluids and which can require emergency intervention, heart attack, hepatitis, jaundice, mental confusion, acute kidney failure and impotence.
But, then, if the drug is saving lives the risk of these life-endangering side effects may just be worth it. But, then again, if the drug isn't delivering those benefits the patient is risking his life for nothing.
And that's exactly what researchers have discovered about the ACE inhibitors, which are dished out to almost every heart patient. But low-risk patients - with a stable heart problem and good left ventricular function - derive absolutely no benefit from the drug.
They tested the ACE inhibitor trandolapril against a placebo in a group of 8,290 heart patients, and found there was no difference in the health and longevity of the two groups. In other words the ACE inhibitor was no better than a sugar pill - except that those taking the drug also ran the risk of hepatitis, acute kidney failure and angiodema.