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Diclofenac for pain and inflammation

Dicloflex, Diclomax, Voltarol

Diclofenac is a medicine called a non-steroidal anti-inflammatory drug. It is also known as 'an NSAID'.

Before you take diclofenac, let your doctor know if you have ever had a bad reaction to any other anti-inflammatory painkiller.

Make sure you take your medication as directed on the label of the pack.

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About diclofenac

Type of medicine

Non-steroidal anti-inflammatory drug (NSAID)

Used for

Pain and inflammation

Also called

Voltarol®; Dicloflex®; Diclomax®; Diclo-SR®; Econac®; Motifene®;
Combination brands: Arthrotec® (diclofenac with misoprostol)

Available as

Tablets, gastro-resistant tablets, prolonged-release tablets and capsules, suppositories, mouthwash

Anti-inflammatory painkillers like diclofenac are sometimes called non-steroidal anti-inflammatory drugs (NSAIDs), or just 'anti-inflammatories'. Diclofenac is given to treat painful conditions such as arthritis, sprains and strains, gout, migraine, dental pain, and pain after surgical operations. It eases pain and reduces inflammation.

Diclofenac works by blocking the effect of chemicals in your body, called cyclo-oxygenase (COX) enzymes. These enzymes help to make other chemicals in the body, called prostaglandins. Prostaglandins are produced at sites of injury or damage, and cause pain and inflammation. By blocking the effect of COX enzymes, fewer prostaglandins are produced, which means pain and inflammation are eased.

There are two forms of diclofenac - diclofenac sodium and diclofenac potassium. The main difference between the two is that diclofenac potassium is absorbed into the body more quickly than diclofenac sodium. A quick action is useful where immediate pain relief is required, and a prolonged action is more useful in reducing inflammation.

Some brands of diclofenac also contain a medicine called misoprostol. One brand is called Arthrotec® and is prescribed for arthritis. Misoprostol helps to protect the stomach against irritation which can be caused by taking diclofenac over a period of time.

Diclofenac is not a suitable medicine for people who have heart disease (such as heart failure), or who have circulatory problems, or who have had a heart attack or a stroke. This is because it has been found that there is a small increased risk of heart attack and stroke in this group of people. Other anti-inflammatory medicines are more suitable for people with these conditions - ask your doctor or pharmacist for advice about an alternative medicine.

Diclofenac is also formulated as skin gels and patches and as eye drops. There is more information about these formulations in the separate medicine leaflets called Diclofenac gel/patch for pain and inflammation, Diclofenac gel for sun damage, and Diclofenac eye drops.

Before taking diclofenac

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking your diclofenac dosage, it is important that your doctor knows:

  • If you have asthma or any other allergic disorder.

  • If you have ever had a stomach or duodenal ulcer, or if you have an inflammatory bowel disorder such as Crohn's disease or ulcerative colitis.

  • If you have a heart condition, or a problem with your blood vessels or circulation.

  • If you are pregnant or breastfeeding.

  • If you have any risk factors for heart disease, including high blood pressure (hypertension), high cholesterol levels, diabetes or smoking.

  • If you have any blood clotting problems.

  • If you have a connective tissue disorder, such as a condition called systemic lupus erythematosus (SLE).

  • If you have problems with the way your liver works, or problems with the way your kidneys work.

  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

  • If you have ever had an allergic reaction to any other NSAID (such as aspirin, naproxen, indometacin, and ibuprofen), or to any other medicine.

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How to take diclofenac

  • Before you start taking diclofenac, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about diclofenac and will provide you with a full list of the side-effects which you may experience from taking it.

  • Take diclofenac exactly as your doctor tells you to. Your doctor or pharmacist will tell you how much to take and how often to take it. You may be asked to take just one dose a day, or several doses each day. This information will also be printed on the label of the pack to remind you.

  • As a general rule, taking diclofenac with a glass of milk or after eating some food can help to reduce side-effects such as indigestion.

  • There are a number of different formulations of diclofenac, such as standard tablets, dispersible tablets, gastro-resistant tablets, and prolonged-release tablets/capsules. On the label of your pack there will be instructions to tell you how to take the type you have been given. For example, dispersible tablets should be taken mixed into a small amount of water, and prolonged-release tablets/capsules must be swallowed whole without chewing. Read and follow the directions on the label carefully.

  • If you forget to take a dose, take it as soon as you remember. If when you remember, it is nearly time for your next dose then take your next dose when it is due but leave out the missed dose. Do not take two doses together to make up for a forgotten dose.

  • If you have been prescribed diclofenac mouthwash, gargle or rinse 15 ml of mouthwash two or three times a day. You can use the mouthwash for up to seven days after dental treatment or six weeks after radiotherapy.

Getting the most from your treatment

  • Your doctor will try to prescribe you the lowest dose for the shortest time in order to reduce the risk of side-effects. If you need to take diclofenac for a long time, your doctor may want to prescribe another medicine along with it to protect your stomach from irritation.

  • Try to keep any regular appointments with your doctor. This is so your doctor can check on your progress, and is especially important if you are taking diclofenac for a long-term condition.

  • If you have asthma, symptoms such as wheeze or breathlessness can be made worse by anti-inflammatories such as diclofenac. If this happens to you, you should stop taking diclofenac and see your doctor as soon as possible.

  • If you buy any medicines, check with a pharmacist that they are safe to take with an anti-inflammatory. This is because you should not take diclofenac with any other anti-inflammatory painkiller, some of which are available in cold and flu remedies which can be bought over the counter in pharmacies and other retail outlets.

  • If you are having an operation or dental treatment, tell the person carrying out the treatment which medicines you are taking.

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Can diclofenac cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with diclofenac. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common diclofenac side-effects

What can I do if I experience this?

Indigestion or heartburn (acid reflux), stomach pain

Try taking your dose after a meal if you are not already doing so. If the discomfort continues, speak with your doctor

Feeling sick (nausea)

Stick to simple meals - avoid rich or spicy foods


Drink plenty of water to replace the lost fluids

Important: if you experience any of the following less common but more serious symptoms, stop taking this medicine and contact your doctor for advice straightaway:

  • If you have any breathing difficulties such as wheeze or breathlessness.

  • If you have any signs of an allergic reaction such as swelling around your mouth or face, or a severe itchy skin rash.

  • If you pass blood or black stools, bring up (vomit) blood, or have severe tummy (abdominal) pains.

Important: Studies have shown that taking diclofenac at higher doses and for long periods of time can increase your risk of having a heart attack or stroke. Seek urgent medical attention if you experience any signs of this, including: chest pain, shortness of breath, weakness or slurred speech.

If you experience any other symptoms which you think may be due to diclofenac, speak with your doctor or pharmacist for further advice.

How to store diclofenac

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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