ASA

Oct 5, 2018

By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

"Don't throw the baby out with the bath water." The story goes that in olden times, water was scarce. That is probably true. On bath day everyone used the same water and it got progressively dirtier. That also sounds reasonable. Now the kicker. The babies were bathed last. At this point the water was so dirty you couldn't see the baby in the water. As such you might accidentally toss them both together. Sounds a little fishy doesn't it? Maybe just change the phrase to, "Bathe babies first". But at least one German writer has linked this phrase to a time where we sold human beings into bondage.

ASA or aspirin has been in the news lately and people's reactions have been surprising. Usually when a study comes out saying a medication isn't as good as we thought, people are happy to quit taking it. I usually have to implore people to check with their doctors before willy nilly stopping all their meds. But I've talked to people who seem outright scared and angry about the suggestion they don't need to take ASA.

ASA does interesting things in the body. It affects the enzyme cyclooxygenase and this decreases the pro-inflammatory chemicals the prostaglandins. We think that decreasing these prostaglandins is what causes ASA to be able to decrease pain and inflammation. We think that the decrease of the prostaglandin E1 in the brain is what causes ASA to be able to decrease fever. ASA also affects platelets. Platelets help your blood to clot. ASA stops the cyclooxygenase enzyme in the platelet from forming thromboxane. This permanently disables the platelet from being able to clot for the life of the platelet which is 7 to 10 days.

Because of this increase in bleeding risk, ASA has fallen out of favor as a pain and fever fighter and taken on a new role. Low dose ASA is now used routinely to prevent heart attacks and strokes in certain patients. Researchers have found that when we give ASA at low doses, it doesn't bother the stomach as much, but still completely knocks out enough platelets to stop blood clots forming in dangerous places. If a blood clot forms in the brain, a part of the brain dies and that is a stroke. If a blood clot forms in a vessel feeding the heart muscle, a piece of the heart muscle dies and that is a heart attack.

Let's look at what the study in the news is saying. First, we need some definitions. Primary prevention when a person takes a treatment to try to prevent a disease that has never happened before in that person. Secondary prevention is a treatment to prevent a disease that has already happened from happening again. Starting in the 1980's researchers found that people who had heart attacks and strokes were less likely to have a second heart attack or stroke if they took ASA. That is secondary prevention. Everyone still agrees on using ASA for secondary prevention. ASA definitely still reduces the chances of heart attack and stroke in people who have had one already.

The Heart Research Institute says every 7 minutes someone in Canada dies of heart disease or stroke. If ASA prevents heart attacks and strokes and it is very inexpensive, why shouldn't we put all adults on it? It is a risk benefit thing. If someone is at a low risk for a heart attack or stroke, previous studies showed ASA only prevents a cardiovascular event once out of every 1000 people on ASA. The problem is the ASA will cause about the same number of serious bleeds in the stomach or the brain. The risk benefit calculation doesn't even change if the patient has just diabetes. Having just diabetes increases your risk of heart attack and stroke, but giving ASA to someone with just diabetes doesn't prevent enough cardiovascular events to outweigh the bleeding risk.

There is a new study in the news that says don't slap ASA into every adult. JJ McNeil et al. published "Effect of Aspirin on All-Cause Mortality in the Healthy Elderly" in the September 16, 2018 New England Journal of Medicine. They looked at healthy people 70 years and over in the US and Australia with no heart disease, dementia or disability. They had 19,114 people enrolled. Half got ASA 100 mg and half got placebo. They were followed for almost 5 years. And the placebo group did not die more often than the ASA group.

What does this study tell us? They looked at healthy older people because they should be the most likely to benefit from ASA. And they didn't. This adds to the evidence that low dose ASA doesn't prevent enough heart attacks and strokes in people without heart disease to justify giving it to everyone. There is an extra complication to this study. Slightly more people in the ASA group died of cancer than in the placebo group. Does this mean ASA causes cancer? Probably not. Other studies have shown ASA reduces cancer rates. So, the slight increase in cancer deaths will have to be investigated further.

Should I throw out my ASA? Of course not. Remember the study were surprisingly healthy 70 plus year olds. No heart disease, no dementia, no other disabilities. Healthy 70 and 80 years olds exist, but most of the people that age who see me in the pharmacy have diabetes, and/or a previous heart attack, and/or previous mini-stroke, and/or a stent and/or an irregular heart beat, and and and. We do know ASA is good a preventing a second (or third or fourth) heart attack or stroke. Most of the people I talk to on ASA already have a heart condition of some kind. They should definitely not stop their ASA.

What if you are a completely healthy 43 year old with absolutely no other health conditions and you put yourself on ASA because someone in your family had a heart attack. Well first you're probably a male and haven't seen a doctor in 20 years. Go see a doctor for a check up. We do know for certain if you actually have high blood pressure, diabetes or high cholesterol and we treat those, we will reduce your heart attack risk. But if you are actually completely healthy, should you stop the ASA? Probably, but since the risks of ASA are also low, maybe check with your doctor first. Just to complicate matters a little more, there is some evidence that after stopping ASA you are more likely than average to form blood clots where they shouldn't be for some period of time.

The Scottish philosopher and German scholar Thomas Carlyle translated "Don't throw the baby out with the bathwater" from German to English in the 1800's. It was in an essay saying slavery was a bad thing. Well that is a little strong. The essay said people shouldn't be slaves, they should just be life long permanent servants who got a salary instead. So not exactly extolling the fundamental dignity of every human being and saying owning another human being is completely wrong. However, that essay had some progressive thoughts in it that shouldn't be dismissed. Or like ASA shouldn't be thrown out with the bathwater.

As always if you have any questions or concerns about these products, ask your pharmacist.

The information in this article is intended as a helpful guide only. It is not intended to be used as a substitute for professional advice. If you have any questions about your medications and what is right for you see your doctor, pharmacist or other health care professional.

We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at www.dcp.ca

NEJM - Effect of Aspirin on All-Cause Mortality in the Healthy Elderly - https://www.nejm.org/doi/full/10.1056/NEJMoa1803955

Heart Research Institute - Heart disease facts - http://www.hricanada.org/about-heart-disease/facts-about-heart-disease

Don't throw the baby out with the bathwater - https://www.phrases.org.uk/meanings/dont-throw-the-baby-out-with-the-bathwater.html

 


Read more Health Articles

Unite Interactive