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Arthritis Health Center

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Pain Relief: How NSAIDs Work

NSAIDs are among the most common pain relievers in the world. And lately, they're among the most controversial. Find out what these anti-inflammatory pills actually do inside your body.

How Do NSAIDs Help Relieve Pain? continued...

Most NSAIDs block both Cox-1 and Cox-2 enzymes. They include the over-the-counter drugs:

Other NSAIDs are available by prescription. They include:

Aspirin has some benefits that other NSAIDs do not. The biggest is that aspirin works against the formation of blood clots. As a result, you are less likely to form the clots that can cause heart attacks and strokes. Other NSAIDs do not have this effect.

Cox-2 inhibitors are a newer form of prescription NSAID. As you might guess, they only affect Cox-2 enzymes and not Cox-1. Two of them -- Bextra and Vioxx -- are no longer sold because of concerns about their side effects. The third, Celebrex, is still available.

What Are the Side Effects from Standard NSAIDs?

Most people who use NSAIDs don't have any serious problems with them. But in some -- especially those who need pain relief regularly -- there can be a downside.

When you swallow a pill, it affects your whole system, not just the part that hurts. So while an NSAID may do a great job of easing your pain, it may also be having other effects -- some of them unwanted -- in other parts of your body.

  • Gastrointestinal Problems

The most common risk of standard NSAIDs is that they can cause ulcers and other problems in your esophagus, stomach, or small intestine.

Why? NSAIDs prevent the creation of prostaglandins, the hormone-like chemicals that cause swelling and increase pain. But that's not all that prostaglandins do. There are actually many different types of prostaglandins in your body.

One type of prostaglandin helps protect the lining of the stomach and GI tract. And the Cox-1 enzyme helps make this prostaglandin. Since regular NSAIDs block Cox-1 enzymes, they slow down the manufacture of this prostaglandin. This is why standard NSAIDs cause high rates of gastrointestinal problems. With its defenses down, your GI tract becomes irritated and damaged by normal gastric acids.

How can NSAIDs affect your blood pressure? NSAIDs reduce the blood flow to the kidneys, which makes them work more slowly. When your kidneys are not working well, fluid builds up in your body. The more fluid in your bloodstream, the higher your blood pressure. It's that simple.

If you take NSAIDs in high doses, the reduced blood flow can permanently damage your kidneys. It can eventually lead to kidney failure and require dialysis.

  • Allergic Reactions

NSAIDs can also cause extreme allergic reactions, especially in people with asthma. Experts aren't sure why. Many specialists recommend that people who have asthma stay away from any NSAID, especially if they have sinus problems or nasal polyps.

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