KEVEYIS® (dichlorphenamide): Treatment for Primary Periodic Paralysis

KEVEYIS, granted orphan drug designation in the United States, is the first and only FDA-approved treatment for hyperkalemic, hypokalemic, and related variants of Primary Periodic Paralysis — an ultra-rare neuromuscular disorder.1

KEVEYIS Has Been Proven to Reduce Attacks in 2 Clinical Studies vs Placebo

KEVEYIS was shown to reduce the number, duration, and severity of attacks of Primary Periodic Paralysis.1

Results in Study 1: Hypokalemic patients treated with KEVEYIS had 2.2 fewer attacks per week than patients treated with placebo. Hyperkalemic patients treated with KEVEYIS had 3.9 fewer attacks per week than patients treated with placebo.2

Results in Study 2: Hyperkalemic patients treated with KEVEYIS had 2.3 fewer attacks per week than patients treated with placebo. For hypokalemic patients, the primary endpoint was the occurrence of an intolerable increase in attack frequency or severity, necessitating withdrawal from the treatment phase. Out of 15 patients, the majority reached acute worsening in the placebo phase.3

KEVEYIS Has a Demonstrated Safety Profile

In study 1, the most common side effects of KEVEYIS were tingling or prickling sensations ("pins and needles"), feeling confused and having trouble paying attention, and changes in taste.1

Flexible Dosing of KEVEYIS

KEVEYIS is a 50 mg tablet that is taken once or twice daily when starting therapy. Dosing can be increased or decreased at weekly intervals (or sooner in case of adverse reactions) based on individual response. The maximum recommended daily dose is 200 mg.1

Questions About KEVEYIS?

If you are a patient or healthcare provider with questions about how to fill a prescription for KEVEYIS, or if you have any other questions related to KEVEYIS, call 844-KEVEYIS (538-3947).

Important Safety Information for KEVEYIS

What is KEVEYIS?

KEVEYIS (pronounced keh-VAY-iss) (dichlorphenamide) is a prescription drug used to treat primary hyperkalemic periodic paralysis, primary hypokalemic periodic paralysis, and other similar diseases.

What should you tell your healthcare provider before taking KEVEYIS?

Tell your doctor if you are allergic to dichlorphenamide or other sulfa drugs; if you take high doses of aspirin, or if you have lung or liver disease; if you are pregnant, plan to become pregnant, or are breastfeeding or plan to breastfeed.

What should you know about KEVEYIS?

  • Severe allergic and other reactions have happened with sulfonamides (drugs such as KEVEYIS) and have sometimes been fatal. Stop taking KEVEYIS at the first sign of skin rash, swelling, difficulty breathing, or any other unexpected side effect or reaction, and call 911 right away.
  • Tell your healthcare provider if you take aspirin or if another healthcare provider instructs you to begin taking aspirin. High doses of aspirin should not be taken with KEVEYIS.
  • KEVEYIS can cause your body to lose potassium, which can lead to heart problems. Your healthcare provider will measure the potassium levels in your blood before you start treatment and at certain times during treatment.
  • Tell your healthcare provider about all other prescription and over-the-counter medicines you take, including supplements, as some medicines can interact with KEVEYIS.
  • While taking KEVEYIS, your body may produce too much acid or may not be able to remove acid from the body. Your healthcare provider may run tests on a regular basis to check for signs of acid buildup.
  • KEVEYIS may increase your risk of falling. Tell your healthcare provider right away if you experience a fall while taking KEVEYIS.
  • The risks of falls and acid buildup are greater in elderly patients.
  • It is not known whether KEVEYIS is safe or effective for people younger than 18 years of age.

What are the most common side effects with KEVEYIS?

The most common side effects are a feeling of numbness, tingling or burning (“pins and needles”) in the toes, feet, hands or fingers; trouble with memory or thinking; feeling confused; and unpleasant taste in the mouth.

These are not all of the possible side effects of KEVEYIS. Call your healthcare provider for medical advice about side effects. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.

Please see KEVEYIS Important Safety Information and Full Prescribing Information.


  1. KEVEYIS [package insert]. Feasterville-Trevose, PA: Strongbridge Biopharma.
  2. Sansone. VA, Burge J, McDermott MP, et al; for the Muscle Study Group. Randomized, placebo-controlled trials of dichlorphenamide in periodic paralysis. Neurology. 2016;86:1408-1416.
  3. Tawil R, McDermott MP, Brown R, et al. Randomized trials of dichlorphenamide in the periodic paralyses. Ann Neurol. 2000;47:46-53.

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