, Volume 76, Issue 4, pp 501–507 | Cite as

Dichlorphenamide: A Review in Primary Periodic Paralyses

  • Sarah L. GreigEmail author
Adis Drug Evaluation


Oral dichlorphenamide (Keveyis™) is a carbonic anhydrase inhibitor that is approved in the USA for the treatment of primary hyperkalaemic and hypokalaemic periodic paralyses and related variants. The efficacy and safety of dichlorphenamide in patients with primary periodic paralyses have been evaluated in four 9-week, randomized, double-blind, placebo-controlled, phase III trials [two parallel-group trials (HOP and HYP) and two crossover trials]. In two trials in patients with hypokalaemic periodic paralysis, dichlorphenamide was associated with a significantly (eightfold) lower paralytic attack rate and fewer patients with acute intolerable worsening compared with placebo. In two trials in patients with hyperkalaemic periodic paralysis, the attack rate was lower with dichlorphenamide than placebo, with this comparison reaching statistical significance in one trial (crossover) but not the other (HYP), although the attack rate was approximately fivefold lower with dichlorphenamide than placebo in the HYP trial. In 52-week, open-label extensions of the HOP and HYP trials, dichlorphenamide provided sustained efficacy in patients with hypokalaemic or hyperkalaemic periodic paralysis. Dichlorphenamide was generally well tolerated in all four phase III trials and during the extension trials; the most common adverse events were paraesthesia, cognitive disorders and dysgeusia. As the first agent to be approved in the USA for this indication, dichlorphenamide is a valuable treatment option for patients with primary hyperkalaemic or hypokalaemic periodic paralysis.


Attack Rate Crossover Trial Periodic Paralysis Hypokalemic Periodic Paralysis Hyperkalemic Periodic Paralysis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



During the peer review process, the manufacturer of dichlorphenamide was also offered an opportunity to review this article. Changes resulting from comments received were made on the basis of scientific and editorial merit.

Compliance with Ethical Standards


The preparation of this review was not supported by any external funding.

Conflicts of interest

Sarah Greig is a salaried employee of Adis/Springer, is responsible for the article content and declares no relevant conflicts of interest.


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.SpringerAucklandNew Zealand

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