It’s been in everyones’ medicine cabinet for decades, and it’s been used to treat headaches, to reduce inflammation, and for anti-platelet activities. But recent news and recommendations seem to be rendering it obsolete. So what’s the story with aspirin? Is it the beginning of the end? Or is there life left in the old dog yet?

Aspirin, or acetylsalicylic acid, was discovered by Edward Stone, an Oxford scientist, in 1763 as a derivative of the willow tree. It was first synthesized by Bayer in 1897 and is one of the most widely used medicines in the world with a suggested 40,000 tons of it consumed worldwide each year. It costs pennies to make and is on the WHO list of Essential Medicines… We can’t live without it… Or can we?

If we look at the indications of aspirin we can systematically ‘tick-it-off’ with newer alternative products that are at least as effective if not more so. If we have a headache there’s paracetamol/acetaminophen—cheap as chips. Have a fever? The same will bring down your temperature. Need a non-steroidal anti-inflammatory? Take an ibuprofen. So with regards to pain and fever management, does it still have a place on the shelf?

It’s well documented that aspirin does have cardio-protective properties, however its use in cardiology is now coming under question. There is limited support for the use of aspirin in primary prevention of heart attacks and strokes, but there is strong evidence for the use of low dose aspirin in secondary prevention of cardiac events, and this is possibly where aspirin can maintain its forte. The FDA doesn’t support the use of aspirin for primary prevention of cardiac event, and now its use in atrial fibrillation (AF) has come under fire. NICE in the UK recently published new guidelines for aspirin use in AF suggesting that there is increasing evidence of limited benefits and that either warfarin or other anticoagulants should be used in its place, with NICE approving apaxiban, rivaroxiban and dabigatran in recent years. And so… Another one bites the dust.

We can’t dismiss the use of aspirin following Percutaneous Coronary Interventions (PCI’s), where it has demonstrable evidence of cardio-protection, as well as its use in dual anti-platelet therapy. However, how long will it be before some newer, better drug takes its place?

So, for other potential uses for aspirin, we have to consider the research that has taken place with regards to cancer prevention. There has been substantial activity in determining whether or not aspirin has any protective activity in this condition, and, until now, Colorectal Cancer (CRC) is the only area that has seemingly offered any promise. The issue is, the studies that have taken place are observational rather than RCT’s (Randomized Controlled Trials), and any conclusions that have been drawn carry very little clinical weight. Consequently, neither the FDA or EMA support the use of aspirin for primary prevention of cancer. In fact the US Preventative Services Task Force (USFST) categorizes it at Level D, which is actually to advise against the use in primary prevention of CRC.

Ironically, as I write, there has been a study released suggesting that taking low-dose aspirin long term may have a drastic effect on reducing the incidence of pancreatic cancer, by almost half. The research group presented results showing a 48% reduction if aspirin were taken for three years, increasing to 60% if taken for 20 years. But given that a study published in 2004 suggested it may actually increase the incidence of pancreatic cancer in women, there is some contradiction in the evidence. At the same time, a study recently published in Nature suggests that aspirin may have a protective effect following diagnosis of breast cancer and breast cancer mortality. However, this too was observational.

With many cancers, we know that lifestyle, genetic and dietary factors can play a large part in the development and incidence of tumors. This is especially true with the likes of colorectal cancer, where diet has been suggested to play a major factor in recurrence and survival. As the clinical studies involving aspirin are all observational, could it just be that aspirin happens to be in the right place at the right time?

We also have to consider the safety profile of the drug. The risk factors associated with aspirin are not exactly negligible and it has a long list of contraindications including GI bleeding, increased stroke risk, and hemorrhage, across a spectrum of patient groups.
Are we just trying to extend the life cycle of an obsolete drug that is cheap and easy to make, rather than admitting that it’s past its sell-by date and we should simply accept it? Or would the biggest mistake be to ignore the undercurrent of evidence that it could still hold therapeutic benefit? We often look back in history for new treatments and derivations of old therapies to deliver the new ones, but is this the end of the road for old faithful?