Posts Tagged ‘asa’

ASA

By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

 

I can’t draw.  No really, producing stick figures are a challenge for me.  My mom is artistic.  Her brother is artistic.  My sister and I are not.  My daughter Emily can draw.  In fact in Emily’s grade 5 report card her teacher suggested she try shading to add some depth to her artwork.  Emily is told to add some shading and I can’t draw a discernible happy face.  It is fascinating when your kids get abilities you never, ever had.

 

Hippocrates must look at his metaphorical children in the same way.  Hippocrates, the Greek healer who is known as the father of western medicine, wrote about powdered willow bark over 2500 years ago.  White willow bark was used to treat pain and fever.  The active ingredient in white willow bark is thought to be salicin.  Salicin is eventually changed in our bodies to salicylic acid and that is the same substance ASA is changed into.  ASA is now used to treat things Hippocrates would have never dreamed of.

 

A couple thousand years after Hippocrates, chemists identified the active ingredient in white willow bark as salicin.  In the late 1800’s chemists at the Germany company Bayer made a synthetic version of salicin.  This eventually became ASA or acetylsalicylic acid.  Bayer gave ASA the trade name Aspirin.

 

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.

 

The Heart and Stroke foundation of Canada 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?  Well it is a risk benefit thing.  If someone is at a low risk for a heart attack or stroke, 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.

 

ASA really starts benefitting people when they have multiple risk factors for heart attack and stroke.  Let’s say the person was over 40, had diabetes, smoked, had high blood pressure, high cholesterol, and a family history of heart disease.  This person is at a significantly higher risk of heart attack and stroke.  Now ASA will prevent enough cardiovascular events to justify the bleeding risk.  Where ASA really comes into its own is secondary prevention.  That means someone has already had a cardiovascular event.  People who have already had a heart attack, mini-stroke, by-pass, stent, a blood expanding a narrowed artery or stroke all are at much higher risk of having another clot causing damage.  These people need to be on a blood thinner and ASA may be the one their doctor chooses.

 

Does daily, long term low dose ASA do other good things?  Maybe.  Researchers now think ASA may also help fight cancer.  In the March 11, 2013 online version of Cancer, Tang et. al looked at the Women’s Health Initiative study and showed women taking ASA had less chance of getting a skin cancer called melanoma.  That’s good, but a previous study looked at the same Women’s Health Initiative study and found ASA did not prevent colorectal cancer.  In March 2012 issues of the Lancet and Lancet Oncology researchers led by Peter Rothwell and John Radcliffe looked at a bunch of ASA trials.  In one meta-analysis they looked at 51 studies in which some people were put on ASA to prevent heart attacks and strokes and some weren’t.  The ones who weren’t put on ASA got cancer more often.  In another paper they looked at 5 big ASA trials to prevent heart attack and stroke.  They were looking to see how cancer spread or metastasized.  Again the people on the ASA had less cancer spread than those not on ASA.  Although these papers are very interesting, they aren’t randomized, double blind placebo controlled trials.  The patients they were looking at were actually heart patients, some of which happened to have cancer.  Ideally we would like to see a large group of people without cancer half be given a sugar pill and half be give low dose ASA.  Then after a number of years the researchers would check to see which group got cancer more often.  Then we would like to see a trial in which a large number of people with cancer are half given a sugar pill and half given ASA and see in which group the cancer spreads the fastest.  That way we would have a better idea if this ASA effect on cancer is real or not.

 

Hippocrates wouldn’t recognize a medical world full of micro-surgeries, MRI machines and gene therapy.  He would recognize ASA if you told him it came from white willow bark.  But like a proud father, I think he would be amazed by the properties it now has and the new amazing properties it might be proven to have just over the horizon.

 

 

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

ASA

By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

 

I like the movie the Matrix.  Yes, some of the reasons I like it are obvious.  I like watching Neo dodge bullets.  I like the freeze frame 360 degree flying through the air fight scenes.  I like Trinity in her skin tight leather outfits.  But what I really like are the mundane things, the little things.  When Neo goes to talk to the Oracle, she isn’t a beautiful goddess living in a fantastic floating emerald castle in the sky.  The Oracle, an all knowing, possibly omnipotent being is a heavy set woman in her 60’s.  She isn’t on a throne but in a tiny apartment kitchen.  The kitchen has a bright window but faded yellow wall paper.  The Oracle is sitting on a stool baking cookies.  She lights up a cigarette after she takes them out of the oven.  These little mundane details make me think the story of the Matrix is more real, and it could really happen.  Little things are important.

 

ASA, also known as acetylsalicylic acid or aspirin, is an important little thing.  ASA or substances like it have been around for a very long time.  White willow bark has been used to treat pain and fever since before we wrote down our history.  Hippocrates, the Greek healer who was the original western physician, wrote about powdered willow bark over 2500 years ago.  The active ingredient in White Willow Bark is thought to be Salicin.  Salicin is eventually changed in our bodies to salicylic acid and that is the same substance ASA is changed into.

 

In the late 1800’s chemists at the Germany company Bayer made a synthetic version of Salicin.  This eventually became ASA or acetylsalicylic acid.  Bayer gave ASA the trade name Aspirin.

 

ASA does interesting things in the body.  It mainly 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 are these little things in your blood that helps it clot.  ASA stops the cyclooxygenase enzyme in the platelet from forming thromboxane.  This means the platelets won’t be able to clot.  ASA permanently disables the platelet from being able to clot for the life of the platelet which is 7 to 10 days.

 

When you go down the pain killer aisle at the pharmacy, you have three main choices: ASA, acetaminophen (or Tylenol) and ibuprofen.  They all treat pain and fever.  Acetaminophen is the safest for most people because it won’t bother the stomach and won’t make you bleed more easily.  However, acetaminophen is also probably the weakest pain and fever fighter.  Ibuprofen and ASA both do a good job on pain and fever and both reduce inflammation, which acetaminophen doesn’t.  Ibuprofen has been more popular lately because although both ASA and ibuprofen can be hard on the stomach, ibuprofen doesn’t increase how much you bleed as much as ASA does.

 

Because of this increase in bleeding, 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.

 

Researchers now think ASA may also help fight cancer.  In March 2012 issues of the Lancet and Lancet Oncology researchers led by Peter Rothwell and John Radcliffe looked at some interesting stuff.  In one meta-analysis they looked at 51 studies in which some people were put on ASA to prevent heart attacks and strokes and some weren’t.  The ones who weren’t put on ASA got cancer more often.  In another paper they looked at 5 big ASA trials to prevent heart attack and stroke.  They were looking to see how cancer spread or metastasized.  Again the people on the ASA had less cancer spread than those not on ASA.  Although these papers are very interesting, they aren’t randomized, double blind placebo controlled trials.  The patients they were looking at were actually heart patients, some of which happened to have cancer.  Ideally we would like to see a large group of people without cancer half be given a sugar pill and half be give low dose ASA.  Then after a number of years the researchers would check to see which group got cancer more often.  Then we would like to see a trial in which a large number of people with cancer are half given a sugar pill and half given ASA and see in which group the cancer spreads the fastest.  That way we would have a better idea if this ASA effect on cancer is real or not.

 

In a medical world full of big expensive surgeries, MRI machines and gene therapy we must not forget about the little things.  We already know that the little, inexpensive ASA pill can prevent heart attacks and strokes in some people.  Maybe in the future we will be able to stay this little ASA thing can prevent cancer too.

 

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

HIGH BLOOD PRESSURE PILLS AND OTC’S

By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

 

The moustache is gone.  It went from barely noticeable to itchy over the first two weeks.  Over the next two weeks it started catching food and now it is gone.  My upper lip does feel a little cold and naked, but I wasn’t really happy with how grey my whiskers were coming in anyway.  I was feeling kinda old.  In case you missed Barret’s talk last week and all the hairy lips around town the last month, Movember has just come to an end.  Now we are onto the season of Santa, kid’s Christmas concerts, and eating and drinking too much.   I have to remember to be nice to my wife and be helpful with the kids so the holiday season doesn’t make Doris’s blood pressure go up too much.

 

If you are on high blood pressure pills and the holidays or the holiday parties give you a headache, what medication should you reach for?  Without a prescription, the most common choices in the pharmacy are ibuprofen, naproxen sodium, ASA and acetaminophen.  Let’s look at how they affect blood pressure and blood pressure pills.

 

The safest choice is acetaminophen.  The brand name for acetaminophen is Tylenol.  Acetaminophen won’t make your blood pressure go up.  Acetaminophen is very unlikely to interact with your blood pressure medications.  The only time we really worry about acetaminophen is if a person has liver problems.  Acetaminophen is broken down by the liver so if a person has liver problems it might need to be avoided.

 

If acetaminophen is so safe, why would someone with high blood pressure take anything else?  Acetaminophen treats pain, but doesn’t treat inflammation.  Some headaches have an inflammatory component.  So some people find acetaminophen doesn’t work that well for their headaches.  What about ASA?

 

ASA or aspirin or acetylsalicylic acid treats both pain and inflammation.  Some people find ASA works very well one their headaches.  The downside to ASA is the blood thinning.  Many people on high blood pressure medications are also on blood thinners.  So if they take ASA with their blood thinners, their blood make get too thin and cause bleeding problems.  What else could someone use?

 

Ibuprofen which goes by the brand name Advil or Motrin, and naproxen sodium which goes by the brand name Aleve are called NSAIDs.  NSAIDs or non-steroidal anti-inflammatories are very good at treating pain and inflammation.  They can be very effective for treating headaches.  The problem with NSAIDs is that they can increase your blood pressure.  NSAIDs are more likely to increase your blood pressure if you are older, male, overweight, have diabetes or certain heart, liver or kidney conditions.

 

Now stop panicking.  I know some of you are on blood pressure pills and have taken an NSAID once in a while for a headache already.  That’s okay.  If you take an NSAID for 2-3 days for a headache, a sore tooth or a sore knee, that won’t be a problem.  But if you have to start using an NSAID everyday for a week or more, let your pharmacist or doctor know.  They may want you to monitor your blood pressure to see what is going on.  How much NSAIDs will affect your blood pressure can depend on which blood pressure pill you are on too.  Calcium channel blockers like nifedipine and amlodipine should be the least affected by NSAIDs.  However, if you are on an ACE inhibitor like ramipril or an ARB like telmisartan plus a diuretic like hydrochlorothiazide, you should probably avoid NSAIDs without checking with your doctor first.

 

Just like itchy lips in Movember, headaches during the holiday season are common.  If you have high blood pressure, acetaminophen is the safest way to treat a headache just like shaving December 1st is the best cure for an itchy mustached lip.  During a board meeting of the MS Society we were discussing, with a little envy, how Movember is close to the perfect fund raiser.  Other than a website, there is no overheard like making meals or supplying safety vehicles like we need to do for the MS Bike Tour.  You don’t have to gather all the participants in one place.  For Movember the participants are all over the world.  And all the monetary pledges are done online.  You don’t have to mail out pledge forms, or collect and count money.  The whole Movember idea is just fabulous from a fund-raising point of view.  And it is fun to look like a 70’s adult film star for a month knowing your wife can’t complain.

 

 

As always if you have any questions or concerns about these or other 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

Antidepressants and Blood Thinners

By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

My dad grew up near Lake Superior in Northern Ontarioin small town called Wawa.  When he grew up, Wawa had no highway connecting it to the rest of Canada and no TV.  My mom grew up just outside of Hamilton in a town called Ancaster.  So my mom was a city girl.  They met when my dad was going to University in Hamilton.  Eventually my dad took my mom back to Wawa.  On one trip he took her moose hunting.  My mom and dad were in one canoe and my grandfather and Edward Nimmon were in another.  My grandfather and Edward went to one end of a peninsula and pushed bush to drive the moose towards my mom and dad at the other end.  My mom described it as a beautiful day.  It was warm.  They tied up their canoe at the bottom of a little six foot cliff, scrambled up the rocks and got comfortable.  They just had to wait until the moose showed up.  Then my mom remembers a distant rustling and cracking noise.  The noise was getting louder.  And louder.  Then in my mom’s mind everything started to shake like an earthquake.  She said, “Bob, I’m scared we have to go!”  My dad gently convinced my mom to stay and got prepared to shoot the moose that was going to pop out of the bush.  But my mom was going to have none of that.  She told my dad she was going to jump off of the 6 foot cliff into the canoe below and paddle away to safety.  Now my dad had a decision to make.  Take the shot at the moose his dad and hunting partner had pushed through the bush or save his wife and their canoe.  So he probably made the right decision and put down his rifle.

 

Human beings are notoriously bad at assessing risk.  My mom was convinced the moose was going to do her such harm that she was willing to jump off a cliff into a canoe.  That would have been an obvious overreaction to the risk she was facing.

 

I had a patient ask me about an article in the Canadian Medical Journal.  The patient had heard an interview with a doctor about this article and it had scared her.  During the interview it was said that if someone was taking an antidepressant and ASA together, the patient would bleed a lot.  The interview said that doctors and pharmacists didn’t know about this interaction.  The interview said maybe patients shouldn’t trust their doctors and pharmacists.  Was this interview an overreaction to the study?  Let’s review what the article said.

 

In the September 26, 2011 edition Labos et al published a paper about the risk of bleeding when a patient took an SSRI and antiplatelet therapy together.  SSRI stands for Selective Serotonin Reuptake inhibitor.  An SSRI is a type of antidepressant.  The original SSRI was prozac, but the class now includes several other products like paxil or paroxetine, zoloft or sertraline and celexa or citalopram.  Antiplatelet agents include ASA and clopidogrel or plavix.  These medications are used to thin the blood to prevent heart attacks and strokes.  They are often given after a patient has a heart attack to prevent another one.  The paper was an interesting read.  The authors did say that if an SSRI and ASA or clopidogrel were taken together the chances of bleeding went up.  And no, I didn’t know about this interaction before I read this study. 

 

The study looked backwards on the records of 27, 058 patients who were over 50 and discharged from the hospital after a heart attack.  The authors followed the records of these patients until they were admitted to the hospital with a bleed, a heart attack, the patient died or the study period ended.  The authors of the study concluded patients on an SSRI plus either ASA or clopidogrel or both have an increase chance of a bleed.  But the study was not perfect.  To begin with it wasn’t a double blind placebo controlled trial.  That means the people running the study weren’t able to control what the study subjects were doing.  For example the authors only knew if a patient filled their ASA by prescription.  They had no idea if a patient went and bought ASA over the counter and used it.  The study authors had no idea if patient bought other things over the counter that cause stomach bleeds like ibuprofen.  The study authors had no idea if the patients actually took their drugs.  They only know the drugs were purchased at a pharmacy.  So although the study results are interesting, they should be confirmed by other studies before we leap to any conclusions.

 

Next let’s assume SSRI’s when given with ASA or clopidogrel increase the chance of a stomach bleed.  Should we never ever put someone on ASA and an SSRI?  As usual we would have to balance the risk versus the benefit.  If we had a patient in her 40’s who was at risk of a stroke and was also depressed, what should we do?  Given such a patient is at low risk of a stomach bleed, the doctor might rightly decide to put her on an SSRI for her depression and ASA to prevent a stroke.  The doctor should monitor the patient for signs of a stomach bleed, but taking the two medications together would be possible.

 

I’m glad this study was brought to my attention.  Although I don’t think an interaction between SSRI’s and antiplatelet medications has conclusively been proven, if possible I will recommend a patient not to take both.  But I don’t want anyone to rush out and throw away either their ASA or their antidepressant.  The risk of a bleed is not 100%.  Your doctor may think the bleeding risk is low in your case.  In any case discuss your concerns with your doctor before you do anything rash.  Otherwise you will be jumping into a canoe from a cliff.

 

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

 

CMAJ article http://www.cmaj.ca/content/early/2011/09/26/cmaj.100912.full.pdf+html

 

Have you heard Trevor on the radio?  Listen to 730 CKDM Tuesday Mornings at 8:35 am!  We now have most of the articles published in the Parkland Shopper on our Website www.dcp.ca

 

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.

Antidepressants and Blood Thinners – Audio

By Trevor Shewfelt.  Recorded by the nice people at 730 CKDM, The Parkland’s Best Music

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