Anti-inflammatories, non-steroidal
Introduction
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 with NSAIDs include:
- headaches
- 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 with 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 side effects, such as stomach ulcers. Therefore, if you are taking NSAIDs to treat a chronic condition, you may need more treatment to reduce your risk of developing side effects. See NSAIDs - special considerations for more information.
How NSAIDs work
NSAIDs work by interfering with certain enzymes in your body. Enzymes are a special type of protein that help to create, 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, which 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, which control the prostaglandins that are involved in pain and inflammation. NSAIDs help to reduce pain and inflammation by preventing COX enzymes from releasing the prostaglandin chemicals that 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
Some of 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:
Aspirin
Aspirin was the first NSAID to be developed in 1897. Aspirin is still widely used in other countries, but in the UK its use as a painkiller has decreased. This is because there are other painkillers with the same level of effectiveness but with a lower risk of side effects, such as ibuprofen and paracetamol (paracetamol is not considered an NSAID).
In the UK, aspirin is now primarily prescribed for its blood-thinning properties. The medical term for blood-thinning medication is antiplatelets medication.
Aspirin is used as a blood-thinning medication because research has found that taking low-dose aspirin can reduce the risk of serious health conditions, such as a heart attack or stroke, in certain high-risk groups. High risk groups include:
- people with a previous history of heart attack or stroke
- people with high blood pressure (hypertension)
- people with diabetes
The routine use of low-dose aspirin for people without a pre-existing risk factor is not recommended because the risks associated with treatment, such as stomach ulcers and internal bleeding, are thought to outweigh any benefits.
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How does it work?
When non-steroidal anti-inflammatory drugs (NSAIDs) were first developed, scientists did not fully understand how they worked. However, now that more research has been carried out in this area, the way NSAIDs work is much better understood.
Enzymes
NSAIDs work by interfering with particular enzymes in your body. Enzymes are a special type of protein which help to either bring about, or speed up, a chemical reaction within your body. For example, digestive enzymes help your digestive system to break up large food particles into smaller pieces so that they can be absorbed by 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 which help to protect the stomach from acid (which is normally present in the stomach). White blood cells contain COX-2 enzymes, which control the prostaglandins that are involved in pain and inflammation.
Prostaglandins
Prostaglandins perform several different functions within your body, such as keeping the lining of your stomach healthy. They are also one of the chemicals responsible for causing pain and inflammation.
NSAIDs can reduce pain and inflammation by preventing COX enzymes from releasing the prostaglandin chemicals which cause pain and inflammation. However, prostaglandins carry out many different functions within your body. Interfering with them can cause a number of different side effects, such as indigestion and stomach ulcers.
COX-2 inhibitors
COX-2 inhibitors are a newer type of NSAID. Like prostaglandins, the COX-2 enzyme causes pain and inflammation within the body, whereas the COX-1 enzyme protects the stomach. Traditional NSAIDs interfere with both enzymes, which means that although they combat pain and inflammation, they also have the potential to damage the stomach.
Specific COX-2 inhibitor
NSAIDs were therefore developed so that the medicine affected the COX-2 enzyme, but not the COX-1 enzyme. It was hoped that the COX-2 inhibitors would treat pain and inflammation, but not affect the stomach.
Although COX-2 inhibitors have less effect on the stomach, they may be more likely to cause side affects on the heart than 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.
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Special considerations
When to avoid NSAIDs
There are a number of situations where the use of non-steroidal anti-inflammatory drugs (NSAIDs) is not recommended, or they should only be used if you are directly instructed to by your GP or another qualified healthcare professional. These situations are outlined below.
Children under 16 years old
Aspirin should never be given to children who are under 16 years of age because there is a small risk that it could trigger a serious and potentially fatal condition called Reye’s syndrome. This condition can cause liver and brain damage. Paracetamol or ibuprofen are a safer alternative.
Pregnant women
The use of NSAIDs during pregnancy is not recommended unless paracetamol does not effectively treat a particular condition. If a NSAID is to be used, ibuprofen is the safest medication during pregnancy.
However, it should be taken at the lowest possible dose to treat symptoms for the shortest possible time. NSAIDs, including ibuprofen, should never been taken from the 30th week of pregnancy onwards.
Breastfeeding women
The use of NSAIDs during breastfeeding is not recommended unless it is felt that the benefits of treatment outweigh the risks to your baby. If a NSAID is to be used, ibuprofen will be recommended at the lowest possible dose for the shortest possible time needed to treat symptoms.
Cautions
Stomach ulcers
NSAIDs can increase your risk of developing stomach ulcers and having internal bleeding, particularly if they are taken on a long-term basis. Therefore, if you have any pre-existing risk factors for stomach ulcers and internal bleeding, you may wish to avoid NSAIDs and use an alternative medication (see below)
Known risk factors for stomach ulcers and internal bleeding are:
- being 65 years of age, or over
- having a history of stomach ulcers, internal bleeding inside your digestive system or previous perforation of your digestive system or bowel
- having an existing condition, such as diabetes, high blood pressure (hypertension), heart disease, liver disease or kidney disease
- taking another medication that is known to increase the risk of stomach ulcers and internal bleeding
Medications that are known to increase the risk of stomach ulcers and internal bleeding include:
- heparin and warfarin, which are used to prevent blood clots
- aspirin, including low-dose aspirin
- corticosteroids, which are used to treat inflammation and suppress the immune system
- the two antidepressants known as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs)
However, there are some health conditions for which long-term use of NSAIDs may be the only effective method of relieving symptoms. For example:
- chronic back pain
- rheumatoid arthritis
- osteoarthritis
If you need to take NSAIDs on a long-term basis and you have an increased risk of developing stomach ulcers and bleeding, you will probably be given an additional medication known as a proton pump inhibitor (PPI).
PPIs help to prevent stomach ulcers and internal bleeding by reducing the production of stomach acid. See Stomach ulcer - treatment for more information about PPIs.
If you are taking a NSAID, avoid smoking and drinking large amounts of alcohol as these activities can increase your risk of developing a stomach ulcer.
Cardiovascular and kidney problems
In rare cases, NSAIDs can damage the kidneys and cardiovascular system (heart and blood vessels). Therefore, the use of NSAIDs is not usually recommended for people with pre-existing risk factors for cardiovascular or kidney conditions. Examples of these include:
For men, heavy alcohol consumption means regularly drinking more than 21 units of alcohol a week. For women, it means regularly drinking more than 14 units of alcohol a week. One unit of alcohol is equal to about half a pint of normal strength beer, one small glass of wine or a pub measure (25ml) of spirits.
If you have one or more of the risk factors listed above and you need to take NSAIDs on a medium- to short-term basis, it is recommended that you have regular blood pressure and kidney function tests.
Asthma
Some people with asthma find that taking a NSAID can make their asthma symptoms more severe. If this happens to you, it is best to avoid taking NSAIDs in the future (unless directly instructed to by your GP or other qualified health professional), and take paracetamol instead.
Alternatives to NSAIDs
If you have been advised not to take NSAIDs, a number of alternative medications can be used.
If you need medication to treat pain, paracetamol can be used as a safer alternative in almost all cases. An exception to this concerns people with severe liver disease because paracetamol will damage the liver.
If you have gout (a condition where crystals form inside the joints, often causing severe pain) a medication called colchicine is an effective alternative to using a NSAID.
Alternative treatments for osteoarthritis include:
- codeine – a mild opiate-based painkiller
- capsaicin cream – which helps block the nerves from sending pain signals to the brain
- corticosteroid injections – these help to reduce the symptoms of pain and swelling
- surgery – such as a hip joint or knee joint replacement
Alternative treatments for rheumatoid arthritis include:
- disease-modifying anti-rheumatic drugs (DMARDs) – a type of medication that can help to ease symptoms and slow down the progression of rheumatoid arthritis
- corticosteroids
See the topics about Gout, Osteoarthritis and Rheumatoid arthritis for more information.
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Side effects
Many people take non-steroidal anti-inflammatory drugs (NSAIDs) without experiencing any side effects. They can be a very effective form of treatment and are widely used to treat a number of conditions.
However, it is important to remember that any medicine can carry the risk of side effects. In a small number of cases, the side effects of NSAIDs can be very serious. This is why if you are taking NSAIDs for a prolonged period of time, or in high doses, your reaction to the medication will be closely monitored.
Some of the side effects that can be caused by NSAIDs are outlined below.
Common side effects
NSAIDs most commonly affect the gastrointestinal tract (your stomach and intestines). Common side effects associated with the long-term use of NSAIDs include:
- indigestion (dyspepsia)
- stomach ulcer (a sore in the lining of the stomach)
Stomach ulcers can sometimes cause more serious complications, such as:
- gastrointestinal bleeding - internal bleeding inside the digestive system
- anaemia - a condition where the blood cannot carry enough oxygen around your body
- gastrointestinal perforation - when a hole occurs in the wall of your stomach
or intestines
Less common side effects
Less commonly, NSAIDs can affect your heart and the rest of the circulatory system.
Side effects can include:
- heart failure
- heart attack
- raised blood pressure (hypertension)
It is important to note that although potentially very serious, these side effects are uncommon, and are most likely to affect someone who has an existing cardiovascular condition.
Research has found that taking NSAIDs on a daily basis causes persistent headaches in around 1 in 10 people.
Some types of NSAID can make people feel drowsy or dizzy. If you have these side effects while taking a NSAID, avoid driving or operating machinery.
Rare side effects
In rare cases, NSAIDs may affect your liver, or kidneys. However, this only happens in a small number of cases and is most likely to affect those with existing liver or kidney conditions.
Reporting side effects
The Yellow Card Scheme allows you to report suspected side effects from any type of medicine that you are taking. It is run by a medicines safety watchdog called the Medicines and Healthcare Products Regulatory Agency (MHRA). See the Yellow Card Scheme website for more information.
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Interactions other medicines
Other medications
You may not always be able to take non-steroidal anti-inflammatory drugs (NSAIDs) in combination with other medicines. This is because some combinations of medicines can cause harmful side effects.
Taking NSAIDs can make certain medicines less effective. This could be potentially dangerous if these other medicines are treating a serious condition, such as high blood pressure (hypertension).
Types of medication that are known to interact with NSAIDs include:
- angiotensin-converting enzyme (ACE) inhibitors, which are often used to treat high blood pressure (hypertension)
- anticoagulants, such as heparin and warfarin, which are often used to prevent blood clots (solid lumps of protein that can sometimes form in the blood)
- ciclosporin which prevents rejection of newly transplanted organs, or bone marrow
- corticosteroids, which are used to help reduce inflammation
- diuretics, which help to reduce the amount of fluid in your body
- hypoglycemics, which are used to treat type 2 diabetes (a condition where there is too much glucose in the blood)
- lithium, which is used to treat depression (prolonged feelings of extreme sadness) and bipolar disorder (manic depression, when your moods swing from one extreme to another)
- methotrexate, which treats rheumatoid arthritis, psoriasis, and various types of cancers
- phenytoin, which is used to treat epilepsy (a condition that causes repeated seizures)
- quinolone, which is a type of antibiotic
- selective serotonin reuptake inhibitors (SSRIs), a type of antidepressant
- serotonin-norepinephrine reuptake inhibitors (SNRIs), a type of antidepressant
Other NSAIDs
It is always best to only use one NSAID at a time. If you are using over-the-counter (OTC) NSAIDs, you should not use aspirin and ibuprofen at the same time. This is because you may be at an increased risk of developing side effects if you use more than one NSAID at a time.
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Interactions - food or alcohol
Alcohol
It is normally safe to drink alcohol while taking, an NSAID, as long as you stick to the recommended daily limits (3-4 units of alcohol a day for men, and 2-3 units for women).
Drinking more than the recommended daily limits of alcohol may irritate your stomach lining. Therefore you may be unable to take NSAIDs if you are going to drink more than the recommended daily limits.
If you drink heavily, and you take an NSAID, your risk of bleeding in your stomach may be increased. Speak to your GP, or pharmacist, if you are unsure whether or not you should be taking NSAIDs.
Food
There are no known interactions between NSAIDs and food. Ideally, take NSAIDs shortly after eating and avoid taking them on an empty stomach. This will help minimise the risk of the medicine upsetting your stomach.
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Dosage
Before prescribing a non-steroidal anti-inflammatory drug (NSAID), your GP will always look to see if there is an alternative form of treatment which may be suitable. This is to help minimise your risk of experiencing any side effects.
If your GP feels that NSAIDs are the most appropriate form of treatment, they will prescribed the lowest effective dose for the shortest period of time necessary.
It is better to prescribe a low dose, over a short period of time and, if necessary, to gradually increase it. By doing this, any side effects should not be as severe.
Effects of specific NSAIDs
Your tolerance to different types of NSAIDs can vary greatly. While one type of NSAID may cause no side-effects, another type may not be as effective or it may have an adverse effect on your gastrointestinal tract, heart, circulation, or kidneys.
Therefore, before prescribing a different type of NSAID, your GP will carefully consider your individual circumstances, and your likelihood of having any sort of reaction to the medicine. Do not switch between NSAIDs unless your GP agrees it is safe for you to do so.
Overdose
It is important to strictly follow all of the instructions about the recommended dosage for your particular NSAID. If you exceed the recommended dose, you risk experiencing a wide range of adverse effects, which could be minor, moderate or serious.
Minor effects of an overdose include:
- upset stomach
- skin irritation
- drowsiness
- rapid heartbeat (tachycardia)
Moderate effects of an overdose include:
- a sudden drop in blood pressure, which can make you feel dizzy and light-headed
- brief seizures (fits)
If you think you or someone else is having mild or moderate effects of an NSAID overdose, contact your GP immediately for advice. If this is not possible, call NHS Direct on 0845 4647.
Serious effects of an overdose include:
- prolonged and repeated seizures (fits)
- serious breathing difficulties
- loss of consciousness
- suddenly stopping breathing
A serious NSAID overdose is a medical emergency. If you think you or someone else is having serious effects of an NSAID overdose, call 999 immediately and ask for an ambulance.
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