Diclofenamide (or dichlorphenamide) is a sulfonamide and a carbonic anhydrase inhibitor of the meta-disulfamoylbenzene class. Dichlorphenamide as a carbonic anhydrase inhibitor is used for the treatment of acute angle closure glaucoma. While Dichlorphenamide does contain two sulfate groups within the structure, it falls under the class of a first generation carbonic anhydrase Inhibitor.
Uses
Diclofenamide was approved in the United States in 1958 as Daranide to treat glaucoma,[1][2][3] Subsequently, it was found effective in cases of therapy-resistant epilepsy.[4] In 2015, the medication was approved in the US under the name Keveyis as an orphan drug for the treatment of primary hypokalemic and hyperkalemic periodic paralysis.[1][5]
Cost
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.[citation needed] 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.[5]
