How do prescription nonsteroidal anti-inflammatory drugs work?
Nonsteroidal anti-inflammatory drugs (also called NSAIDs) stop cyclooxygenase enzymes (also called COX enzymes) in your body from working. COX enzymes speed up your body's production of hormone-like substances called prostaglandins. Prostaglandins cause the feeling of pain by irritating your nerve endings. They are also part of the system that helps your body control its temperature.
By reducing the level of prostaglandins in your body, NSAIDs help relieve pain from conditions like arthritis. They also help reduce inflammation (swelling), lower fevers and prevent blood from clotting.
What are some common prescription NSAIDs?
There are 2 classes of prescription NSAIDs.
Traditional NSAIDs include the following:
- Mefenamic Acid
COX-2 inhibitors include celecoxib.
If you need to take a prescription NSAID, your doctor will help you find one that is right for you.
What's the main difference between traditional NSAIDs and COX-2 inhibitors?
You have 2 types of COX enzymes in your body: COX-1 and COX-2. Researchers believe that one of the jobs of COX-1 enzymes is to help protect your stomach lining. The COX-2 enzyme doesn't play a role in protecting your stomach.
Traditional NSAIDs stop both COX-1 and COX- 2 enzymes from doing their jobs. When COX-1 enzymes are blocked, pain and inflammation is reduced, but the protective lining of your stomach is also reduced. This can cause problems such as upset stomach, ulcers, bloating and bleeding in your stomach and intestines.
COX-2 inhibitors only stop COX-2 enzymes from working. Since the COX-2 enzyme doesn't help to protect your stomach, COX-2 inhibitors may be less likely to irritate your stomach or intestines.
Do prescription NSAIDs have any side effects?
Like all medicines, these drugs can cause side effects. However, the side effects usually are not severe and are not experienced very often.
Common side effects of prescription NSAIDs may include the following:
- Excess gas
- Extreme weakness or fatigue
- Dry mouth
Serious side effects of prescription NSAIDs may include the following:
- Allergic reaction, such as difficulty breathing, hives, swelling of the lips, tongue or face
- Muscle cramps, numbness or tingling
- Rapid weight gain
- Black, bloody or tarry stools
- Bloody urine or bloody vomit
- Decreased hearing or ringing in the ears (also called tinnitus)
- Jaundice (the yellowing of the skin and the whites of the eyes)
- Abdominal cramping
In addition to the side effects listed above, people taking a COX-2 inhibitor may be at risk for the following side effects:
- Swelling or water retention
- Skin rash or itching
- Unusual bruising or bleeding
- Difficulty sleeping (insomnia)
Call your doctor as soon as possible if your side effects become severe.
Is it safe to take NSAIDs for a long period of time?
People who take NSAIDs increase their risk of developing severe bleeding in their stomachs. They may also be at risk for heart attacks and strokes. These risks gets worse if they take higher doses and/or if they take these medicines for a long period of time. Patients who need to take pain medicine for longer than a week should discuss this risk and explore other pain treatment options with their family doctor.
What is a drug interaction?
If you use 2 or more drugs at the same time, the way your body processes each drug can change. When this happens, the risk of side effects from each drug increases and each drug may not work the way it should. This is called a drug-drug interaction. Vitamins and herbal supplements can affect the way your body processes drugs, also.
Certain foods or drinks can also prevent your medicine from working the way it should or make side effects worse. This is called a drug-food interaction. For example, if you're taking a traditional NSAID, drinking alcohol can increase your risk of liver disease or stomach bleeding.
Drug-drug interactions and drug-food interactions can be dangerous. Be certain that your doctor knows all of the over-the-counter and prescription medicines, vitamins and herbal supplements that you are taking. Also, talk to your doctor before you take any new over-the-counter or prescription medicine or use a vitamin or herbal supplement.
It's important to take medicines exactly as your doctor prescribes. Ask your doctor whether you need to avoid any foods or drinks while using a prescription NSAID.
Written by familydoctor.org editorial staff