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 the tablets/capsules as directed on the label of the pack.
|Type of medicine||Non-steroidal anti-inflammatory drug (NSAID)|
|Used for||Pain and inflammation|
|Also called||Voltarol®; Dicloflex®; Diclomax®; Volsaid®; Arthrotec® (contains diclofenac with misoprostol)|
|Available as||Tablets and dispersible tablets, gastro-resistant tablets, prolonged-release tablets and capsules, suppositories, mouthwash|
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, heartburn, 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||Stick to simple meals - avoid rich or spicy foods|
|Diarrhoea||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 diclofenac 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.
If you experience any other symptoms which you think may be due to diclofenac, speak with your doctor or pharmacist for further advice.
Diclofenac interactions and warnings
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 high blood pressure.
- 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.
Dosage and formulations
- 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, unless it is nearly time for your next dose. In which case, take your next dose when it is due and 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.
How diclofenac works
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 is available on prescription.
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. The brands are called Arthrotec® and Misofen®, and are 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, 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.
Further reading and references
Manufacturer's PIL, Diclofenac sodium 25 mg and 50 mg gastro-resistant tablets; Dexcel Pharma Ltd, The electronic Medicines Compendium. Dated November 2016
British National Formulary 74th Edition (Sep 2017); British Medical Association and Royal Pharmaceutical Society of Great Britain, London.