Arthrotec (Diclofenac, misoprostol)
How does it work?
Arthrotec tablets contain two active ingredients, diclofenac and misoprostol. Diclofenac is a type of medicine called a non-steroidal anti-inflammatory drug (NSAID) and is used to relieve pain and inflammation in arthritis. Misoprostol is used to prevent the potential side effects of diclofenac on the gut.
Diclofenac works by blocking the action of a substance in the body called cyclo-oxygenase (COX). Cyclo-oxygenase is involved in producing prostaglandins, in response to injury or certain diseases, such as arthritis. These prostaglandins cause pain, swelling and inflammation. Diclofenac blocks the production of these prostaglandins and so is effective at relieving pain and inflammation.
However, cyclo-oxygenase does not only produce prostaglandins that cause inflammation. It also produces prostaglandins that have useful roles in the body, including some that are involved in maintaining a healthy stomach and intestinal lining. These prostaglandins reduce the amount of acid produced by the stomach and increase bicarbonate and mucus secretion in the gut, which normally protects the linings of the gut from stomach acid.
Diclofenac reduces the production of these gut protective prostaglandins and so can damage the gut lining, causing ulcers, bleeding and sometimes even perforation (holes) in the gut.
Misoprostol is a type of medicine called a prostaglandin analogue. It mimicks the action of the gut protecting prostaglandins and is included in Arthrotec tablets to counteract the potential adverse effects of diclofenac on the gut. This helps to prevent ulcers that might otherwise be caused by the diclofenac.
What is it used for?
- Preventing ulcers in the stomach or intestines in people who need to take diclofenac to relieve the pain and inflammation of rheumatoid arthritis or osteoarthritis.
Arthrotec is usually only prescribed to people who need to keep taking an NSAID to relieve the pain of their arthritis, but who are at a high risk of getting an ulcer, for example because they are elderly, have previously had a peptic ulcer, or are taking diclofenac long-term or at a high dose.
How do I take it?
- The dose prescribed and how often to take the medicine depends on your level of pain and inflammation and the strength of tablet you have been prescribed. It is important to follow the instructions given by your doctor. These will also be printed on the dispensing label that your pharmacist has put on the packet of medicine. If you are unsure about anything, talk to your pharmacist.
- Arthrotec tablets should be taken with or after food. They should be swallowed whole with a drink and not broken, chewed or crushed.
- Try to space your doses evenly. If you forget to take a dose at your usual time take it as soon as you remember, unless it is nearly time for your next dose. In this case just leave out the forgotten dose and take the next dose as usual. Do not take a double dose to make up for a missed dose.
- This medicine may cause dizziness, drowsiness or visual disturbances and so may affect your ability to drive or operate machinery safely. Do not drive or operate machinery until you know how this medicine affects you and you are sure it won't affect your performance.
- This medicine may mask the signs and symptoms of infection, such as fever and inflammation. This may make you think mistakenly that an infection is getting better when it isn't, or that an infection is less serious than it is. For this reason you should tell your doctor if you get an infection while you are taking this medicine.
- Your doctor will prescribe you the lowest effective dose of this medicine for the shortest possible time necessary to relieve your symptoms. This is to minimise the chances of any side effects, particularly those mentioned below. It is important not to exceed the prescribed dose.
- Although the misoprostol in Arthrotec is included to reduce the risk of diclofenac side effects on the gut, these types of side effects are still possible. They are more likely to occur in elderly people and in people taking high doses of the medicine. The risk can also be increased by taking certain other medicines (see below). It is important that these people, as well as people with a history of disorders affecting the stomach or intestines, are closely monitored by a doctor while taking this medicine. All people taking this medicine should stop treatment and consult their doctor immediately if they experience any sign of bleeding from the stomach or intestine during treatment, for example vomiting blood and/or passing black/tarry/bloodstained stools.
- In recent years research has shown that use of diclofenac is associated with a small increase in the risk of having a heart attack or stroke. The risks increase with higher doses and the longer the medicine is taken. These risks are very rare and the benefits of the medicine for pain relief still outweigh these risks for most people. However, if you have existing heart or blood vessel disease (see below) the latest advice is that diclofenac is not suitable for you. Your doctor can prescribe you a different painkiller that has lower risks for you. If you have risk factors for heart disease or stroke, such as diabetes, high blood pressure, high cholesterol or smoking, your doctor will need to assess the overall benefits and risks before deciding if this medicine is suitable for you. Ask your doctor or pharmacist for further information.
- Very rarely, NSAIDS may cause serious blistering or peeling skin reactions (eg Stevens-Johnson syndrome, toxic epidermal necrolysis, exfoliative dermatitis). For this reason, you should stop taking this medicine and consult your doctor if you get a skin rash or sores inside your mouth while taking this medicine. This side effect is very rare, but if it occurs, is most likely to happen in the first month of treatment.
- If you have any problems with your heart, liver or kidneys your kidney function should be regularly monitored while you are taking this medicine.
- During long-term treatment with this medicine you should have regular check-ups with your doctor so that you can be monitored for possible side effects of the medicine. This might include routine blood tests to monitor your kidney function, liver function and levels of blood components, particularly if you are elderly.
Use with caution in
- Elderly people.
- People with a history of disorders affecting the stomach or intestines, such as ulceration or bleeding.
- Inflammatory bowel disease such as Crohn's disease or ulcerative colitis.
- Decreased kidney function.
- Decreased liver function.
- A type of life long inherited blood disease caused by a defect in the liver (hepatic porphyria).
- People with a history of high blood pressure (hypertension).
- People with raised levels of fats such as cholesterol in their blood (hyperlipidaemia).
- History of asthma.
- History of allergies.
- People with blood clotting disorders or taking anticoagulant medicines.
- Diseases affecting connective tissue, eg systemic lupus erythematosus.
Not to be used in
- Children under 18 years of age.
- Women planning a pregnancy. (Women who could get pregnant must use an effective method of contraception to prevent pregnancy while taking this medicine - see below).
- People in whom aspirin or other NSAIDs, eg ibuprofen, cause allergic reactions such as asthma attacks, itchy rash (urticaria), nasal inflammation (rhinitis) or swelling of the lips, tongue and throat (angioedema).
- People with an active peptic ulcer, perforation (hole) or bleeding in the gut.
- People with other active bleeding, eg in the brain.
- Heart failure.
- Heart disease caused by inadequate blood flow to the heart (ischaemic heart disease), eg angina or history of heart attack.
- People with disease of the blood vessels in and around the brain (cerebrovascular disease), eg history of stroke or mini-stroke (TIA).
- People with poor circulation in the arteries of the legs or feet (peripheral arterial disease).
- Severe liver failure.
- Severe kidney failure.
- Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Arthrotec tablets contain lactose).
This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.
If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.
Pregnancy and breastfeeding
Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.
- This medicine must not be used by women who are pregnant, or who are planning a pregnancy, because it can be harmful to an unborn baby. Misoprostol mimicks the effects of prostaglandins involved in starting labour and causes contractions of the womb. This could result in a miscarriage. Diclofenac may delay labour, increase the length of labour and cause complications in the newborn baby. Some evidence suggests that NSAIDs should also be avoided by women attempting to conceive, as they may temporarily reduce female fertility during treatment and may also increase the risk of miscarriage or malformations.
- Women who could get pregnant must use an effective method of contraception to prevent pregnancy while they are taking this medicine. Seek medical advice from your doctor. If you think you could be pregnant at any point during treatment you should stop taking this medicine and consult your doctor immediately.
- Diclofenac and misoprostol pass into breast milk in small amounts. The diclofenac is unlikely to be harmful to a nursing infant, however the misoprostol could potentially cause diarrhoea in a nursing infant. For this reason, the manufacturer states that this medicine should not be used by women who are breastfeeding. Seek further medical advice from your doctor.
- Take this medication with or after food.
- This medication is to be swallowed whole, not chewed.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
Very common (affect more than 1 in 10 people)
- Abdominal pain.
Common (affect between 1 in 10 and 1 in 100 people)
- Difficulty sleeping (insomnia).
- Wind (flatulence).
- Inflammation of the stomach (gastritis).
- Peptic ulcer.
- Skin reactions such as rash or itching.
- Alteration in results of liver function tests.
Uncommon (affect between 1 in 100 and 1 in 1000 people)
- Inflammation of the mouth.
- Vaginal bleeding.
- Decreased numbers of platelets in the blood (thrombocytopenia).
Rare (affect between 1 in 1000 and 1 in 10,000 people)
- Inflammation of the liver (hepatitis).
- Yellowing of the skin and whites of the eyes (jaundice).
- Severe swelling of the face, throat, lips and tongue (angioedema).
- Visual disturbances such as blurred or double vision.
- Sensation of ringing or other noise in the ears (tinnitus).
- Loss of appetite.
- Decreased numbers of white blood cells or red blood cells in the blood.
- Irritability, depression or anxiety.
- Feeling confused or disorientated.
- Taste disturbances.
- Pins and needles sensations.
- Retention of fluid causing swelling (oedema).
- Dry mouth.
- Bleeding or perforation (holes) in the gut - see warning section above.
- Changes in blood pressure.
- Shortness of breath or asthma attack.
- Stroke (cerebrovascular accident).
- Chest pain or palpitations.
- Heart attack (myocardial infarction) or heart failure - see warning section above.
- Severe allergic skin reactions - see warning section above.
- Kidney problems, including acute kidney failure.
- Liver problems, including liver failure.
- Inflammation of the bowel (colitis) or pancreas (pancreatitis).
The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before taking this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.
There may be an increased chance of diarrhoea if magnesium-containing antacids are taken with this medicine. If you need to take an antacid while you are taking this medicine, ask your pharmacist for advice on which ones are most suitable, and don't take it within two hours of taking your Arthrotec tablet.
Diclofenac should not be taken in combination with painkilling doses of aspirin or any other oral NSAID, eg ibuprofen, naproxen, as this increases the risk of side effects on the stomach and intestines. Selective inhibitors of COX-2 such as celecoxib or etoricoxib should also be avoided for the same reason.
There may be an increased risk of ulceration or bleeding from the gut if diclofenac is taken with oral corticosteroids such as prednisolone.
There may be an increased risk of bleeding, particularly from the gut, if diclofenac is taken with any of the following medicines:
- anti-blood-clotting (anticoagulant) medicines such as warfarin, dabigatran, heparin
- anti-platelet medicines to reduce the risk of blood clots or 'thin the blood', eg low-dose aspirin, clopidogrel, dipyridamole
- SSRI antidepressants, eg fluoxetine, paroxetine, citalopram
Diclofenac may reduce the removal of the following medicines from the body and so may increase the blood levels and risk of side effects of these medicines. People taking diclofenac with any of these should be closely monitored by their doctor:
There may be an increased risk of side effects on the kidneys if diclofenac is taken with any of the following medicines:
- ACE inhibitors, eg enalapril
- angiotensin II receptor antagonists, eg losartan
- diuretics, eg furosemide
Diclofenac may oppose the blood pressure lowering effects of certain medicines to treat high blood pressure, such as the following:
- ACE inhibitors such as captopril
- angiotensin II receptor antagonists, eg losartan
- beta-blockers such as propranolol
- diuretics such as furosemide.
There may be an increased risk of seizures (fits) if diclofenac is used in combination with quinolone antibiotics, such as ciprofloxacin or ofloxacin.
Ciclosporin and the antifungal voriconazole may both increase the blood level of diclofenac, and your doctor may prescribe a lower than normal dose of diclofenac if you are taking one of these.
Rifampicin may increase the breakdown of diclofenac and it may be less effective in people taking this medicine for tuberculosis.
Other medicines containing the same active ingredient
There are currently no other medicines available in the UK that contain both these active ingredients. Diclofenac and misoprostol are both available separately.