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.
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
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
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
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
High Blood Pressure and Kidney Damage
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
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.
How Are Cox-2 inhibitors Like Celebrex Different?
Cox-2 Inhibitors are a type of NSAID, and generally they work in similar
ways. They are no better or worse at relieving pain. They have most of the same
But there is a vital difference. Cox-2 inhibitors were specifically designed
to avoid the gastrointestinal problems common to other NSAIDs.
Most NSAIDs affect levels of both Cox-1 and Cox-2 enzymes. Cox-2 inhibitors
only block the Cox-2 enzyme. So these drugs don't affect the prostaglandins
that protect the lining of your GI tract. Cox-2 inhibitors offer the same pain
relief as standard NSAIDs, but a much lower risk of gastrointestinal
What Are the Risks of Cox-2 Inhibitors?
In a normal body, the levels of Cox-1 and Cox-2 enzymes are naturally in
balance. When you block one but not the other, unexpected things can
It turns out that the Cox-1 enzymes also help make a chemical that
encourages blood clotting and tightens the arteries. Normally, these nasty
effects are kept in check by another chemical called prostacyclin. But
prostacyclin is made, in part, with the help of Cox-2 enzymes -- the enzymes
that drugs like Celebrex block.
Blocking only Cox-2 upsets the balance of these enzymes. Levels of
prostacyclin go down, the influence of Cox-1 goes unchecked, and your risk of
heart attacks and strokes goes up.
This is why Cox-2 inhibitors have been linked to an increased risk of heart
attacks and strokes. The dangers were considered so high for the drug Vioxx
that it was taken off the market. Bextra, another Cox-2 inhibitor, was also
removed from the market partly because of the same risk.
Published Oct. 4, 2005.