My wife takes a statin tablet to lower her cholesterol. For reasons of economy, it has been suggested that she change from Lipitor (also known as atorvastatin) to simvastatin. Is there any difference in their effects?

Dr Fred Kavalier answers your health question:

Statins have been described by the British Medical Journal as "one of the great success stories of preventive medicine". They are credited with preventing heart attacks, strokes and illnesses linked to high cholesterol levels. In 2004, the NHS spent 738m on statins. The two main statin drugs prescribed - simvastatin and atorvastatin - account for much of this. The National Institute for Health and Clinical Excellence suggests that 14 per cent of adults should take statins. The usual simvastatin dose is either 20mg or 40mg a day; for atorvastatin it is 10mg or 20mg a day. Simvastatin (no longer protected by a patent) is much cheaper. Although you need to take more simvastatin for an equivalent effect, the drugs do much the same thing and are equally safe and effective. As with all drugs, some patients will get side effects on one but not another. Every time a patient is started on simvastatin rather than atorvastatin, the NHS expects to save about 1,000 over five years. Changing patients from atorvastatin to simvastatin could save the NHS 2bn in five years. The argument for using simvastatin seems pretty convincing to me.

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