Diclofenac
In this section
Does it work?
What is it?
How can it help?
Why should it work?
Can it be harmful?
What's the evidence?
Does it work?
If you have a migraine headache, you are more likely to feel better if you take diclofenac than if you don't take any medicine at all. And diclofenac may make your headache go away completely.What is it?
Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID). There are different ways of taking diclofenac. Your doctor may prescribe it as a pill or an injection. The brand names are Voltarol and Diclomax.How can it help?
Diclofenac can make a migraine attack less severe and may make it go away completely. It can also shorten an attack.Here is what the research found.
- One study found that diclofenac gave headache relief to more than 3 in 10 people taking 50 milligrams (mg) and about 4 in 10 people taking 100 mg.1
- Another study found that diclofenac made migraine headaches bearable or made headaches last for less than two hours in 2 in 10 to 3 in 10 people who took it.2
- Of the people in the above studies who took a dummy treatment for comparison (a placebo), about 2 in 10 had the same improvement in their symptoms.1 2
- If you take diclofenac, you are less likely to need to take other painkillers for your headache.
- Diclofenac injections can reduce headache pain quite quickly. In some people they work within 35 minutes.3 More than 4 in 10 people who have injections find their migraine symptoms get better within one hour.4
- Diclofenac injections can also help if you have migraine with aura. One study found it relieved headaches for 5 in 10 people who had migraines with auras.4 (To learn more about migraines with auras, see What is migraines?)
- Another study found that diclofenac injections work better than paracetamol injections.3
- Diclofenac may also relieve other symptoms of an attack, such as being extra-sensitive to light or sound. It may also help you get back to your normal routine faster.
Why should it work?
Like other NSAIDs, diclofenac works by stopping your body making chemicals called prostaglandins. Your body makes these chemicals when you are in pain or injured. Prostaglandins cause inflammation and make you more sensitive to pain. By stopping the prostaglandins, diclofenac can help you feel better.Can it be harmful?
The drawback of diclofenac and other NSAIDs is that they can irritate the lining of your stomach. This may cause stomach ulcers or bleeding in your stomach. It's usually best not to take NSAIDs if you have a stomach ulcer or if you've had one in the past.About 1 in 3 people who take diclofenac for migraine have side effects, including stomach pain and tiredness.5 In the studies we looked at, most people rated these problems as mild or moderate. But 1 in 8 people rated their side effects as severe.2 5
In one study of 170 people, stomach problems were the most common side effect of diclofenac.2 But only three people withdrew from the study or stopped taking the drug because of this.
You should not take diclofenac if you are allergic to this drug or any of the ingredients in tablets containing diclofenac, aspirin or other NSAIDs (such as ibuprofen). You should not take it if you are in the last three months of pregnancy.
You should also be cautious about taking diclofenac if you have:
- Heart failure
- High blood pressure
- Liver or kidney problems.
Diclofenac can interact with a wide range of other medicines, including blood-pressure drugs such as ACE inhibitors and diuretics (water pills), as well as blood thinners (anticoagulants) and corticosteroids. If you are taking prescription medicines, check with your doctor before you take diclofenac.
Guidelines for doctors on NSAIDs also say that if you need an NSAID you should:
- Start on the lowest recommended dose
- Not use more than one NSAID at a time.
Taking high doses of NSAIDs every day for a long time may increase your risk of a heart attack or a stroke. This is unlikely to be a problem with the doses you take for a migraine. But if you'd like to read more, see Warnings about side effects of NSAIDs.
What's the evidence?
What's the evidence for diclofenac?Sources for the information on this page:
- Dahlof C, Bjorkman R. Diclofenac-K (50 and 100 mg) and placebo in the acute treatment of migraine. Cephalalgia. 1993; 13: 117-123.[PubMed]
- Massiou H, Serrurier D, Lasserre O, et al. Effectiveness of oral diclofenac in the acute treatment of common migraine attacks: a double-blind study versus placebo. Cephalalgia. 1991; 11: 59-63.[PubMed]
- Karachalios GN, Fotiadou A, Chrisikos N, et al. Treatment of acute migraine attack with diclofenac sodium: a double-blind study. Headache. 1992; 32: 98-100.[PubMed]
- Bigal ME, Bordini CA, Speciali JG. Intramuscular diclofenac in the acute treatment of migraine: a double-blind placebo controlled study. [In Portuguese] Arquivos de Neuro-psiquiatria. 2002; 60: 410-415.[PubMed]
- The Diclofenac-K/Sumatriptan Migraine Study Group. Acute treatment of migraine attacks: efficacy and safety of nonsteroidal anti-inflammatory drug, diclofenac-potassium in comparison to oral sumatriptan and placebo. Cephalalgia. 1999; 19: 232-240.[PubMed]
- British National Formulary. Non-steroidal anti-inflammatory drugs. Section 10.1.1. BNF 55. March 2008. British National Formulary. Available at: http://www.bnf.org/ (accessed on 24 July 2008).
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