Diclofenac

What is diclofenac?

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID). It’s commonly used to relieve pain and reduce inflammation[4].  

Diclofenac works by blocking substances in the body called prostaglandins – these play a key role in causing inflammation, pain, and fever[4]. 

What is diclofenac used for?

Diclofenac is commonly prescribed for conditions such as osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis (arthritis of the spine). It may also be prescribed for acute migraine attacks, menstrual cramps, and mild to moderate pain, such as pain from injury or surgery.[4] 

How does diclofenac work?

Diclofenac works by inhibiting enzymes known as COX-1 and COX-2 (cyclooxygenase enzymes). These help produce prostaglandins, which trigger inflammation and pain. In reducing prostaglandin levels, diclofenac helps relieve pain, reduce swelling, and lower fever[4]. 

Who can take diclofenac?

Diclofenac is generally suitable for adults under medical supervision. It’s not typically recommended for children, unless specifically prescribed in cases like[4]: 

• Tablets, capsules and use suppositories from 12 months, for arthritis 

• Gel if they're 14 years old or over 

• Plasters and patches if they're 16 years old or over 

Older adults may use diclofenac, but with caution. It is generally less suitable for those more vulnerable to side effects such as stomach ulcers, kidney issues, or heart problems. 

Pregnant women should avoid diclofenac especially during the third trimester, as it may harm the baby. If you are breastfeeding, speak with your doctor or pharmacist before using diclofenac as data on safety is currently limited. 

Please tell your doctor or pharmacist about any conditions you may have before starting diclofenac, and always follow the instructions in the Patient Information Leaflet[5].

What is the typical dosage of diclofenac?

Your diclofenac dose depends on how you take or use it, since it comes in tablet, capsule, suppository, gel, plaster and patch form[4]. 

For tablets or capsules, the usual dose is from 75 mg to a maximum of 150mg a day[4].  

Always follow your doctor’s instructions and read the patient leaflet that comes with the medicine[5]. 

How do you take diclofenac?

Diclofenac comes in different forms, including oral tablets or capsules that you can swallow with a glass of water. It’s best to take diclofenac with food to help protect your stomach[4]. 

Topical gels patches or plasters can also be found in pharmacies which you can apply directly to the painful area as directed by your doctor or pharmacist. Do not to crush or chew extended-release tablets or capsules[4]. 

Can you stop taking diclofenac suddenly?

Yes, you can stop taking diclofenac if you’re using it for short-term temporary pain relief and the pain has gone away[4].  

However, if you are on long-term treatment (such as for arthritis), speak to your doctor or pharmacist before stopping. Suddenly stopping long-term use without medical advice could result in your symptoms returning or getting worse. 

What should you do if you take too much diclofenac?

Using too diclofenac in gel, plaster or patch form is unlikely to cause harm. However, when taken orally or as suppositories, an overdose of diclofenac can be dangerous. The signs of such an overdose may include nausea and vomiting, stomach pain, drowsiness, breathing problems, or seizures. Seek emergency medical help if you think you have taken too much diclofenac[4]. 

What should you do if you forget a dose of diclofenac?

If you forget to take a dose of diclofenac, take it as soon as you remember. If it is almost time for your next dose, you should skip the missed one and continue your schedule as normal. Do not double the dose to make up for a missed tablet as this may cause serious effects. 

What medications can or can't be taken with diclofenac?

Diclofenac may interact with other medicines. As such, you should avoid using it with a range of other treatments, including[4]: 

• Other NSAIDs like ibuprofen and naproxen 

• Blood thinners (e.g., warfarin), which may increase the risk of bleeding 

• SSRIs (e.g., fluoxetine), as they may increase bleeding risk 

• Diuretics and ACE inhibitors or ARBs (e.g., lisinopril, losartan), as these may affect kidney function 

Diclofenac may be safe to take with paracetamol. In some cases, it can also be taken with certain antidepressants, but always under medical supervision.

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[5]. 

What are the side effects of diclofenac?

The most common side effects of diclofenac include stomach pain, nausea, headaches, diarrhoea and dizziness. In some cases, more serious side effects can occur, including[4]: 

• Chest pain or shortness of breath  

• Black or bloody stools  

• Severe stomach pain 

• Swelling of the legs or ankles 

• Yellowing of the skin or the whites of your eyes 

If you notice any of these serious symptoms, stop taking diclofenac and contact a doctor or pharmacist immediately.

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice.

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[5].

Frequently asked questions about diclofenac

Can I drink alcohol while taking diclofenac? 

It is best to avoid alcohol while taking diclofenac. This is because it can increase your risk of stomach bleeding[4]. 

Is diclofenac addictive? 

No, diclofenac generally is not addictive and does not cause dependence. Always follow the instructions provided by your doctor or pharmacist[4]. 

Can I use diclofenac gel and tablets together? 

Sometimes, your doctor or pharmacist may recommend using both diclofenac tablets and gel together. However, this should only be done under medical guidance to avoid exceeding the safe dose[4].

For the official NHS guide to diclofenac, visit their website.