Diclofenac
Sounds like 'dye-KLOE-fen-ak'
Key points about diclofenac
- Diclofenac is an anti-inflammatory used to treat pain and inflammation.
- Diclofenac is also called Voltaren®, Diclohexal® or Apo-Diclo SR®.
- Find out how to take it safely and possible side effects.

Diclofenac is in a group of medicines known as non-steroidal anti-inflammatory drugs (NSAIDs). It's used to treat different types of pain such dental pain, period pain, bursitis, migraine and pain resulting from injury or after surgery.
NSAIDs are also used to ease pain, swelling and stiffness associated with flare-ups of gout, osteoarthritis, rheumatoid arthritis and ankylosing spondylitis. NSAIDs block the inflammation process and in this way ease swelling and pain.
In New Zealand diclofenac comes as tablets, dispersible (dissolvable) tablets, suppositories and an injection.
- Tablets comes as immediate release and slow release (SR).
- The immediate release tablets are useful where immediate pain relief is required, and the slow release is more useful in reducing long term inflammation.
- The suppositories are useful when tablets are unsuitable, eg, for migraine which may involve vomiting. Learn more about suppositories.
Lower strengths of diclofenac tablets and capsules (Voltaren Rapid®) can be bought from a pharmacy without a prescription.
- The dose of diclofenac will be different for different people depending on its use.
- Immediate release tablets: The usual dose is 25 to 50 mg, 2 or 3 times a day.
- Slow release tablets: The usual dose is 75 to 100 mg in 1 or 2 divided doses.
- Usually, you only need to take diclofenac for a short time, just while you have pain and swelling.
- Tablets and capsules
- Swallow the tablets and capsules whole with a glass of water.
- Don't crush or chew them.
- If diclofenac causes stomach upset, take it with or soon after food.
- Dispersible tablets
- Dissolve the tablet in some water. Stir if necessary.
- After taking, rinse the container with water and drink this to ensure all the diclofenac dose is swallowed.
- If diclofenac causes stomach upset, take it with or soon after food.
- Stay hydrated while taking diclofenac to protect your kidneys.
- Avoid or limit alcohol while you're taking diclofenac. Alcohol can increase the risk of side effects like stomach upset.
- Missed dose: If you forget to take a dose, take it when you next need pain relief and then continue as before. Don't take 2 doses together to make up for a missed dose.
For most people taking diclofenac is safe, but extra care is needed in some situations. For example if:
- you have high blood pressure
- you have heart or kidney problems or asthma
- you're aged 65 years or older
- you smoke.
It can be harmful if you take diclofenac when you are dehydrated or have been sick with diarrhoea (runny poos) or vomiting (being sick). Read more about the risks of NSAIDs.
When you should NOT take diclofenac |
Diclofenac should NOT be used in some situations as it can be harmful.
Read more about the risks associated with NSAIDs. |
Don't take other anti-inflammatory medicines such as ibuprofen, naproxen or celecoxib while taking diclofenac.
It's safe to take diclofenac with paracetamol because they work differently.
Diclofenac interacts with some medicines, especially those used for high blood pressure, so check with your doctor or pharmacist before you start taking diclofenac.
Image credit: Healthify He Puna Waiora
Taking NSAIDs together with blood pressure medicines can be harmful to your kidneys. This is called the ‘triple whammy’. If you are taking blood pressure medicines (ACE inhibitors or ARBs) and diuretics tell your doctor or pharmacist before starting diclofenac. Talk to them about safe pain-relief options for you.
- Examples of ACE inhibitors are captopril, cilazapril, enalapril, lisinopril, perindopril and quinapril.
- Examples of ARBs are candesartan, irbesartan and losartan.
- Examples of diuretics are furosemide, bumetanide, bendroflumethiazide, chlortalidone, indapamide, spironolactone, eplerenone and metolazone.
Read more about the triple whammy.(external link)
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Read more about medicines and side effects and reporting a reaction you think might be a side effect. |
The following links have more information on diclofenac:
Diclofenac(external link) (te reo Māori(external link)) NZ Formulary Patient Information
References
- Diclofenac sodium (systemic)(external link) New Zealand Formulary
Brochures
Medicines and side effects
Healthify He Puna Waiora, NZ, 2024
Health Quality and Safety Commission, NZ, 2019 English, te reo Māori
Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.
Reviewed by: Angela Lambie, Pharmacist, Auckland
Last reviewed:
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