|Systematic (IUPAC) name|
|Trade names||Ponstel, Ponstan|
|Biological half-life||2 hours|
|Excretion||Urine (66%), faeces (20-25%)|
|ATC code||M01AG01 (WHO)|
|Molar mass||241.285 g/mol|
|(what is this?)|
Mefenamic acid is a member of the anthranilic acid derivatives (or fenamate) class of NSAID drugs, and is used to treat mild to moderate pain, including menstrual pain, and is sometimes used to prevent migraines associated with menstruation. It is not widely used due to its side effects.:334
Its name derives from its systematic name, dimethylphenylaminobenzoic acid. It was discovered and brought to market by Parke-Davis in the 1960s under brandnames Ponstan, Ponstan Forte, Ponalar, Ponstyl, and Ponstel. It became generic in the 1980s and is available worldwide under many brand names. As of 2015 the cost for a typical course of medication in the United States is more than 200 USD.
There is evidence that supports the use of mefenamic acid for perimenstrual migraine headache prophylaxis, with treatment starting 2 days prior to the onset of flow or 1 day prior to the expected onset of the headache and continuing for the duration of menstruation. A study also showed mefenamic acid to be a well tolerated analgesic for post-surgical pain in dental operations.
Mefenamic acid is recommended to be taken with food.
Known mild side effects of mefenamic acid include headaches, nervousness and vomiting. Serious side effects may include diarrhea, hematemesis (vomiting blood), haematuria (blood in urine), blurred vision, skin rash, itching and swelling, sore throat and fever.:334 It has been associated with acute liver damage.
Mechanism of action
Scientists led by Claude Winder from Parke-Davis invented mefenamic acid in 1961, along with fellow members of the class of anthranilic acid derivatives, flufenamic acid in 1963 and meclofenamate sodium in 1964.:718 U.S. Patent 3,138,636 on the drug was issued in 1964.:918–919
Society and culture
Mefenamic acid is generic and is available worldwide under many brand names.
In the USA, wholesale price of a week's supply of generic mefenamic acid has been quoted as $426.90 in 2014. Brand-name Ponstel is $571.70. In contrast, in the UK, a weeks supply is £1.66, or £8.17 for branded Ponstan. In the Philippines, 10 tablets of 500 mg generic mefenamic acid cost PHP39.00 (or the equivalent of $0.88USD)as of October 25, 2014.
- FDA Ponstel Label Updated February 19, 2008
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- FDA March 2008 FDA advisory
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- US Patent 3,138,636
- Marshall Sittig Pharmaceutical Manufacturing Encyclopedia Volume 1 A-K Second Edition, Reprint Edition. Noyes Publications, 1988
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- https://www.medicinescomplete.com/mc/bnf/current/PHP6487-mefenamic-acid-non-proprietary.htm accessed 19th sept 2014
- MedlinePlus Drug Information: Mefenamic Acid. Last accessed September 28, 2005.
- Ponstel Pharmacology, Pharmacokinetics, Studies, Metabolism - Mefenamic Acid - RxList Monographs. Last accessed September 28, 2005.
- Consumption of NSAIDs and the Development of Congestive Heart Failure in Elderly Patients
- NSAIDs May Increase Risk for Worsening Heart Failure