Non-steroidal anti-inflammatory drugs (NSAIDs) are a widely used class of medication that have three main uses:
- to relieve pain
- to reduce inflammation
- to bring down a high temperature (fever)
NSAIDs are available in tablet form and also as a topical treatment (a cream, gel or lotion that is rubbed in to a specific part of the body). Less commonly, NSAIDs are used as a suppository; a capsule that is inserted into the rectum (back passage).
Conditions treated with NSAIDs
NSAIDs are used to treat a wide range of acute (short-term) and chronic (long-term) conditions.
Some common acute conditions that can be treated using NSAIDs include:
- headache
- painful periods
- infections, such as the common cold or the flu (NSAIDs do not treat the underlying infections, but they can help to relieve the symptoms)
Some common chronic conditions that can be treated using NSAIDs include:
- most types of arthritis, including rheumatoid arthritis or osteoarthritis
- back pain
- neck pain
The long-term use of NSAIDs increases your risk of experiencing side effects, such as stomach ulcers. Therefore, if you are taking NSAIDs to treat a chronic condition, you may require additional treatment in order to reduce your risk of developing side effects. See NSAIDs - special considerations for more information.
How NSAIDs work
NSAIDs work by interfering with particular enzymes in your body. Enzymes are a special type of protein that help to bring about, or speed up, a chemical reaction within your body.
NSAIDs interfere with an enzyme called cyclo-oxyganase (COX). Different parts of your body have different types of COX enzymes which control the production of chemicals called prostaglandins.
Different prostaglandins have different functions.
For example, the stomach contains COX-1 enzymes that control the production of prostaglandins that help to protect the stomach from acid (which is usually present in the stomach). COX-1 enzymes also keep your blood relatively sticky, which helps to prevent excessive bleeding.
White blood cells contain COX-2 enzymes that control the prostaglandins that are involved in pain and inflammation. NSAIDs can therefore help to reduce pain and inflammation by preventing COX enzymes from releasing the prostaglandin chemicals which cause pain and inflammation.
As NSAIDs block the effects of the COX-1 enzyme on the blood, they can also be used as a blood thinning medication in people who have a high risk of developing a blood clot.
However, because prostaglandins carry out many different functions within the body, interfering with them can cause a number of different side effects, such as indigestion and stomach ulcers.
Types of NSAIDs
There are two main types of NSAIDs:
- non-selective NSAIDs - such as ibuprofen, which block the effects of both COX-1 and COX-2 enzymes
- COX-2 inhibitors - such as celecoxib, which only block the effects of COX-2 enzymes
COX-2 inhibitors were designed to treat chronic conditions that cause pain and inflammation without affecting the stomach.
Although COX-2 inhibitors have less effect on the stomach, they may be more likely to cause side affects on the heart compared with traditional NSAIDs. This means that they may be more suitable for someone who is at risk of developing stomach or intestinal problems, but less suitable for those with a heart or circulation problem.
Names
The most commonly prescribed NSAIDs are:
- diclofenac
- ibuprofen
- naproxen
- celecoxib
- mefenamic acid
- etoricoxib
- indometacin
Most of the NSAIDs listed above are generic medicines. This means that their production and distribution is not limited to a single company. Therefore, they are available under a range of different brand names.
The exceptions are:
- celecoxib - which is sold under the brand name Celebrex
- mefenamic acid - which is sold under the brand name Ponstan
- etoricoxib - which is sold under the brand name Arcoxia
Two NSAIDs are available over-the-counter (OTC) without the need for a prescription. They are:
See the box to the left for more information about aspirin.