BMA Concise Guide to Medicine & Drugs

Diclofenac

Brand names Defenac, Dicloflex, Diclomax SR, Dyloject, Motifene, Rhumalgan, Voltarol, and many others

Used in the following combined preparation Arthrotec (with misoprostol)

QUICK REFERENCE

Drug group Non-steroidal anti-inflammatory drug, analgesic, and drug for gout

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes (most preparations)

Available as generic Yes

GENERAL INFORMATION

Taken as a single dose, diclofenac has analgesic properties similar to those of paracetamol. It is taken to relieve mild to moderate headache, menstrual pain, and pain following minor surgery. When given regularly over a long period, it has an anti-inflammatory effect and is used to relieve pain and stiffness associated with rheumatoid arthritis and advanced osteoarthritis. It may also be prescribed to treat acute gout attacks, and is given as eye drops to relieve eye inflammation.

The combined preparation, Arthrotec, contains diclofenac and misoprostol. Misoprostol helps prevent gastroduodenal ulceration, which is sometimes caused by diclofenac, and may be particularly useful in patients at risk of developing this problem.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, SR-tablets, dispersible tablets, capsules, SR-capsules, injection, suppositories, gel, eye drops.

Frequency and timing of doses 1–3 x daily with food.

Adult dosage range 75–150mg daily.

Onset of effect Around 1 hour (pain relief); full anti-inflammatory effect may take 2 weeks.

Duration of action Up to 12 hours; up to 24 hours (SR-preparations).

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug When taken for short-term pain relief, diclofenac can be safely stopped as soon as you no longer need it. If prescribed for long-term treatment (e.g. for arthritis), speak to your doctor before stopping the drug.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms or if a large overdose has been taken, notify your doctor.

POSSIBLE ADVERSE EFFECTS

The most common adverse effects are gastrointestinal disturbances, such as heartburn, indigestion, nausea, and vomiting. More rarely, headache, dizziness, drowsiness, swelling of the feet or legs, or weight gain may occur. If any of these symptoms are severe, discuss with your doctor. If the drug causes a rash, itching, wheezing, breathlessness, or black or bloodstained vomit or faeces, you should stop taking it and consult your doctor without delay.

INTERACTIONS

General note Interacts with other NSAIDs, oral anticoagulants, corticosteroids, and SSRI antidepressants to increase the risk of bleeding and/or peptic ulceration.

Ciclosporin and tacrolimus Diclofenac may increase the risk of kidney problems.

Antihypertensive drugs and diuretics The beneficial effects of these drugs may be reduced with diclofenac.

Lithium, digoxin, and methotrexate Diclofenac may increase the blood levels of these drugs to an undesirable extent.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have long-term liver or kidney problems.

· You have a bleeding disorder.

· You have had a peptic ulcer or suffer from indigestion.

· You have porphyria.

· You are allergic to aspirin or other NSAIDs.

· You have asthma, heart problems, or high blood pressure.

· You are taking other medicines.

Pregnancy The drug may increase the risks of adverse effects on the baby’s heart and may prolong labour if taken in the third trimester. Discuss with your doctor.

Breast-feeding Small amounts of the drug pass into the breast milk, but adverse effects on the baby are unlikely. Discuss with your doctor.

Infants and children Reduced dose necessary.

Over 60 Increased risk of adverse effects. Reduced dose may be necessary.

Driving and hazardous work Avoid such activities until you have learned how diclofenac affects you; the drug can cause dizziness, drowsiness and vertigo.

Alcohol Avoid. Alcohol may increase the risk of stomach irritation.

Surgery and general anaesthetics Discuss with your doctor or dentist before any surgery.

PROLONGED USE

There is an increased risk of ulceration, perforation, or bleeding from the bowel wall with prolonged use of diclofenac. There is also a small risk of a heart attack or stroke. To minimize these risks, the lowest effective dose is given for the shortest duration.