What is Mefenamic acid

Mefenamic acid is a prescription-only (POM) medication used to treat mild to moderate period pain and inflammation.

Belonging to a well-known family of medication called NSAIDs (non-steroidal anti-inflammatory drugs), mefenamic acid is used for pain and inflammation in conditions like osteoarthritis and period pain.

Other well known NSAIDs include naproxen and ibuprofen.

What is Mefenamic Acid Used For

Whilst it can generally be used for most conditions involving pain and inflammation, like dental pain, muscle aches or headaches, it is frequently used for two particular conditions:

• Severe period pain (dysmenorrhoea)

• Heavy menstrual bleeding (menorrhagia)

How Does Mefenamic Acid Work For Period Pain

During the menstrual cycle, the body releases chemicals called prostaglandins. These are responsible for uterine contractions during menstruation, which help to shed the uterine lining, leading to the period bleed.

For most individuals, this leads to the usual mild cramps and stomach pain associated with a period. For some however, the prostaglandins cause severe cramping and pains, often even after the period has stopped.

Mefenamic acid works by blocking a specific enzyme called COX which produces these prostaglandins. In doing so, it helps to reduce pain and cramping.

What is The Dose of Mefenamic Acid for Period Pain

The typical dose for period pain is 500mg taken three times daily.
Tablets should be taken as soon as the pain starts. It does not need to be taken everyday, only during the day symptoms are experienced and should usually not be taken for more than 7 days in the same cycle.

Doses should be spread evenly throughout the day, not exceeding a maximum of 3 tablets per day and should be taken with or after food. It's easier to remember if taken alongside breakfast, lunch and dinner.

What Are the Side Effects

As with all medications, mefenamic acid can cause side effects though not everyone gets them. The most common side effects are related to the stomach and gut and include:

• Stomach discomfort - Heartburn, indigestion, acid reflux or mild abdominal pain

• Changes in bowel movements - Diarrhoea or constipation

• Nausea or vomiting

• Headache or dizziness

Serious side effects include:

• Severe diarrhoea

• Signs of stomach bleeding, such as vomiting blood (coffee grounds vomit), or passing dark, tarry stools

• Allergic reactions - such as skin rashes, or swelling of the face, throat, neck and breathing difficulties

• Kidney or liver changes - swelling of the ankles, passing less urine than normal, severe tiredness or yellowing of the eyes or skin.

If you notice any of these side effects, you should stop taking mefenamic acid and seek immediate medical attention.

Who Should Not Take Mefenamic Acid

Whilst mefenamic acid is safe for most, it should not be taken by anyone with the following:

• Allergies to mefenamic acid or any of the other ingredients

• Inflammatory bowel disease

• A history of gastrointestinal bleeding with previous NSAID use

• Active, or a history of stomach ulcers or stomach bleeding

• Severe heart failure

• Kidney failure

• Liver failure

• Anyone who has shown a hypersensitivity reaction to other NSAIDS

  • Asthma, bronchospasm, rhinitis, angioedema or hives

• Last trimester of pregnancy.

Additionally, mefenamic acid should be used in caution by the following groups:

• Anyone with uncontrolled asthma as mefenamic acid can cause severe airway tightening

• The elderly, who are more likely to experience stomach bleeding

• History of high blood pressure or stroke, as NSAIDs cause fluid retention and a small increased risk of heart attack

• Epilepsy - as an overdose may induce seizures

• Dehydration - as this can increase the risk of kidney failure.

Can You Take Mefenamic Acid With Paracetamol or Ibuprofen

Yes, mefenamic acid can be taken with paracetamol. Whilst both help with pain, they do so through different mechanisms. Paracetamol acts primarily in the brain, helping to block pain signals reaching the painful area. NSAIDS act locally at the site where pain is experienced.

The recommended doses for both are to take mefenamic acid up to three times daily, with breakfast, lunch and dinner. As paracetamol doesn’t need to be taken with food, it can be taken in between mefenamic acid doses if needed for added relief.

You cannot take mefenamic acid with ibuprofen. Both are NSAIDS, taking them together effectively duplicates therapy. This will not provide double pain relief but can significantly increase the risk of dangerous side effects.

Mefenamic Acid vs Ibuprofen - Which Is Better For Periods.

Both mefenamic acid and ibuprofen are NSAIDS. They both block the COX enzyme, reducing prostaglandin production, thus helping with contractions, inflammation and pain.

A study evaluating the effectiveness of both drugs in 150 women concluded there was no difference in pain relief between the two treatments, both were equally effective.

The difference occurs for those who also experience heavy bleeding (menorrhagia) alongside the pain. Mefenamic acid not only reduces production of prostaglandins, it additionally blocks existing prostaglandins from binding to the uterus wall, helping to reduce menstrual blood loss by 20-50%.

Is Mefenamic Acid Available Over-the-Counter In The UK

No, Mefenamic acid is a prescription-only (POM) medication. It is not available to purchase over the counter and can only be supplied in accordance with a valid prescription from a registered prescriber.

Whilst some NSAIDs, such as ibuprofen can be purchased over-the-counter, mefenamic acid is restricted due to its higher risk of certain side effects, like severe diarrhoea, and places strain on the kidneys and liver, requiring monitoring before issuing.

How to get Mefenamic Acid from Quick Meds

To get mefenamic acid from Quick Meds, simply head to our period pain section and fill out an online consultation. This will ask about your symptoms, your medical history and if you are taking any other medication.

One of our GPhC-registered prescribers will review your request, ensuring the treatment is appropriate and safe. Once approved, orders are packed securely in plain, discreet packaging and sent via tracked delivery methods as soon as the next day.