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  #1  
Old 04-16-2001, 08:49 PM
Jois Jois is offline
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I got the order from my doc not to take aspirin anymore. I whined a little and he said that it isn't what the aspirin does right then and there to your stomach but what it does after it goes in the blood stream and to the stomach.

What and how does aspirin do to the stomach?

Jois
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  #2  
Old 04-16-2001, 09:12 PM
Terminus Est Terminus Est is online now
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Aspirin is the brand name for acetylsalicylic acid. If you already have problems with acid in your stomach, then putting more acid in there isn't going to help much. From the Asprin FAQ:

Quote:
[L]ess than six percent of the population cannot take acetylsalicylic acid due to stomach upset.... People who are allergic to acetylsalicylic acid, or have asthma, persisting or recurring stomach problems (such as heartburn, upset stomach or stomach pain), ulcers or bleeding problems should not take acetylsalicylic acid unless directed by a doctor. Also, children and teenagers presenting febrile diseases should not take acetylsalicylic acid without prior consultation of a doctor.
You also shouldn't take aspirin if you have Reye's syndrome, taking anticoagulants, or certain other medications.

IANADoctor. Standard disclaimers apply.
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Old 04-16-2001, 09:24 PM
LisaRx LisaRx is offline
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Prostaglandins are a protective component of the stomach lining.

Aspirin interferes in the synthesis of prostaglandins.

It causes a double whammy--the direct "caustic" effect plus preventing the stomach lining from protecting or "healing" itself.

Kind of a simplified explanation. If you need to know more, look at http://www.berkleywellness.com/subCo...RA00Dec09.html

If you do have ulcers, it's important to know that you cannot take enteric coated aspirin, baby aspirin, or buffered aspirin. They're all no-no's.
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Old 04-16-2001, 09:27 PM
KarlGauss KarlGauss is offline
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Your doc is right.

Although aspirin (ASA) has a slight local effect on the stomach to promote ulcers, its major action in causing ulcers has to do with its ability to decrease prostaglandin synthesis (see below). This is a so-called "systemic" effect meaning that however the ASA gets into the body, the effect still occurs, i.e. once it's in the bloodstream (after oral ingestion, rectal adminstration, whatever), it will tend to cause stomach ulcers.

Prostaglandins protect the stomach from the effects of stomach acid (it's a bit of a miracle that the stomach doesn't digest itself). ASA prevents the production of prostaglandins. Stomach ulcers can result.

Why do we still try to prevent prostaglandin production if they're so important to protect the stomach? Well, prostaglandins are what cause a lot of the pain and inflammation of arthritis. So, drugs that decrease prostaglandins also decrease arthritis (and other) inflammation and pain.

So-called COX2 inhibitors have the ability to selectively prevent the production of prostaglandins at sites of inflammation but not in the stomach. They should cause fewer ulcers for equal degrees of anti-arthritis effect, and this seems to be the case.

This page seems to be superb regarding ASA and the stomach and ulcers.
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Old 04-16-2001, 10:09 PM
Smeghead Smeghead is offline
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Dadgummit. You all beat me to it. Now I'm forced to add more than anyone ever wanted to know, just to show off my knowledge.

The enzyme cyclooxygenase (COX) makes prostaglandins from arachidonic acid, which is found in phospholipid membranes. Prostaglandins, as has been mentioned, are important signal molecules. They are involved in the pain response, and also in maintaining the stomach lining. They also seem to have a harmful effect on the heart, which is why aspirin is supposed to be good for people with heart conditions. The COX active site is a long thin channel right up the middle of the enzyme, since both arachidonic acid and prostaglandins are long thin molecules. There's a constricted point just inside the entrance to this channel. Aspirin binds to this point and blocks up the channel, preventing prostaglandin production.

Without prostaglandins, you don't get pain, but your stomach lining also degrades over time. But then it was discovered that, joy of joys, COX actually exists in two forms, COX-1 and COX-2. COX-1 is in charge of maintaining the stomach lining, and COX-2 is in charge of pain. So the new COX-2 inhibitors that KarlGauss mentioned block pain without hurting the stomach. Unfortunately, it appears that the heart benefit from aspirin is mediated by COX-1, so the COX-2 inhibitors do nothing for your heart.

Taa-daa! I told you it would be more than you wanted to know. It's so hard being overeducated...
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  #6  
Old 04-17-2001, 09:08 AM
Jois Jois is offline
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Thank you, Terminus Est, LisaRx, KarlGauss, and Smeghead! Since I have to give up what I consider the greatest medication ever discovered by man or beast, I am delighted, even enchanted, to now know exactly why.

Jois
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