|Drug class||Carbonic anhydrase inhibitor|
|Main uses||Hyperkalemic periodic paralysis, hypokalemic periodic paralysis|
|Side effects||Numbness, change in taste, confusion|
|Chemical and physical data|
|Molar mass||305.14 g·mol−1|
|3D model (JSmol)|
|Melting point||228.5 °C (443.3 °F)|
|(what is this?)|
Diclofenamide, also known as dichlorphenamide, is a medication used to treat hyperkalemic periodic paralysis and hypokalemic periodic paralysis. Evidence of benefit; however, is weak. It is taken by mouth. It has previously been used to treat glaucoma.
Common side effects include numbness, change in taste, and confusion. Other side effects may include anaphylaxis, low potassium, metabolic acidosis, and falls. Safety in pregnancy is unclear. It is a carbonic anhydrase inhibitor.
Diclofenamide was approved for medical use in the United States in 1958. They; however, were not approved for periodic paralysis until 2016. It was granted orphan medicine status in Europe in 2016; however the request for approval was withdrawn in 2019. In the United States 100 tablets of 50 mg costs about 26,000 USD as of 2021.
It was originally used to treat glaucoma. In 2015, the medication was approved in the US as an orphan drug for the treatment of primary hypokalemic and hyperkalemic periodic paralysis. Evidence of benefit; however, is not strong.
In 2001, diclofenamide had a U.S. list price of $50 for a bottle of 100 pills, and was approved for glaucoma. Merck discontinued diclofenamide when better glaucoma drugs were developed. In 2010, Sun Pharmaceutical Industries bought the rights. In 2015, the F.D.A. approved it as an orphan drug, with 7-year exclusive marketing rights, for periodic paralysis, which the company estimates affects 5,000 people in the U.S. In 2016, Strongbridge Biopharma acquired Sun, which raised the price to $15,001 for 100 pills. The cost of treatment would range from $109,500 to $219,000 a year. Sun gives the drug free to patients who don't have insurance.
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- International Drug Names: Diclofenamide
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