AHFS/Drugs.com Monograph Routes ofadministration by mouth Molar mass 241.285 g/mol Bioavailability 90% | MedlinePlus a681028 ATC code M01AG01 (WHO) CAS ID 61-68-7 Protein binding 90% | |
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Trade names Ponstel, Ponstan, others Pregnancycategory AU: CUS: C (Risk not ruled out) | ||
Ponstan pandemonium
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 in the United States due to its side effects.
Contents
- Ponstan pandemonium
- Medical use
- Side effects
- Mechanism of action
- History
- Availability and pricing
- Synthesis
- Research
- References
Its name derives from its systematic name, dimethylphenylaminobenzoic acid. It was discovered and brought to market by Parke-Davis in the 1960s. 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.
Medical use
Mefenamic acid is used to treat moderate pain and menstrual pain.
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.
Side effects
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), hematuria (blood in urine), blurred vision, skin rash, itching and swelling, sore throat and fever. It has been associated with acute liver damage.
In 2008 the US label was updated with a warning concerning a risk of premature closure of the ductus arteriosus in pregnancy.
Mechanism of action
Like other members of the anthranilic acid derivatives (or fenamate) class of NSAID drugs, it inhibits both isoforms of COX and prevents formation of prostaglandins.
History
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. U.S. Patent 3,138,636 on the drug was issued in 1964.
It was approved in the UK in 1963 as "Ponstan", in West Germany in 1964 as "Ponalar", and in France as "Ponstyl" and the US in 1967 as "Ponstel".
Availability and pricing
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.
Synthesis
Analogous to fenamic acid, this compound may be made from 2-chlorobenzoic acid and 2,3-dimethylaniline.
Research
While studies have been conducted to see if mefenamic acid can improve behavior in transgenic mouse models of Alzheimer's disease there is no good evidence that mefenamic acid or other NSAIDs can treat or prevent Alzheimer's in humans; clinical trials of NSAIDs other than mefenamic acid for treatment of Alzheimer's have found more harm than benefit.