Evidence shows aspirin cannot be promoted as an agent for primary prevention of cardiovascular problems.

It has been called a 2,000-year-old wonder drug. The father of modern medicine, Hippocrates, is recorded to have used this drug - extracted from the bark of the willow tree - to relieve pain and fever.

In modern times, aspirin or acetylsalicylic acid is one of the cheapest and widely used drugs produced the world over, costing less than a rupee.

It acquired the wonder drug tag, when it was discovered in the mid-20th century, apart from being an anti-inflammatory, anti-pyretic, analgesic drug, it also had anti-blood clotting and cardiovascular protective properties.

The Physicians’ Health Study in the U.S, in which some 22,000 physicians became participants in a clinical trial involving aspirin, reported that aspirin reduced the risk of first myocardial infarction by 44 per cent (July 20, 1989 New England Journal of Medicine)

Aspirin again created quite a sensation in 2011, when a Lancet study, which involved review of five long-term studies involving over 17,000 patients, reported that low doses of daily aspirin lowered the risk of colo-rectal cancers by 46 per cent.

But then, the halo surrounding the miracle drug has significantly dimmed in the recent years, with clear evidence that aspirin cannot be promoted as an agent for primary prevention of cardiovascular events.

Bleeds and strokes

The risk of serious gastrointestinal bleeds and strokes due to cerebral haemorrhage was slightly on the higher side for those normal, low-risk category persons who had been prescribed daily aspirin.

“Earlier, we believed that an aspirin a day prevented a heart attack. But recent evidence indicates that the preventive effect of aspirin on CVD risk is just a little over 10 per cent and that daily low dose of aspirin is only indicated for those who have a clear CVD risk or those who have had a prior cardiovascular event,” says Tiny Nair, a cardiologist.

Despite studies promoting the beneficial effects of daily aspirin against colo-rectal cancers, aspirin has not been indicated as a cancer-prevention drug. The cancer-prevention benefits attributed to aspirin should be weighed against a person’s relative risk of developing colo-rectal cancer in his lifetime, Dr. Nair points out.

“Aspirin is a very good drug but no international body has confirmed through trials that normal, healthy persons with low CVD risk will benefit from a daily dose of aspirin. Indiscriminate use of this medicine can be dangerous as it can result in gastric or cerebral bleeds,” says Mathew Thomas, a senior consultant physician.

Has the wonder drug ceased to be one? In the European Heart Journal (Oct 17, 2013), cardiologists John G. Cleland and Peter C. Elwood concludes: “There is no evidence that aspirin is effective for the primary prevention of cardiovascular events…indeed, there is no evidence that long-term aspirin should be given to patients even with known cardiovascular disease… the benefits of aspirin, if they exist, may be so small that a very large study would be required to demonstrate that its benefits outweigh its risks.”