KEVEYIS® (dichlorphenamide): Treatment for Primary Periodic Paralysis

The first-and-only FDA-approved treatment for hyperkalemic, hypokalemic, and related variants of Primary Periodic Paralysis (PPP)1

KEVEYIS helped patients gain greater control of PPP1-3

  • KEVEYIS decreased the number, severity, and duration of attacks vs placebo1-3

KEVEYIS has long-term data from a 1-year, open-label extension study2*

  • Median attack rate was lower at 1 year for patients who stayed on KEVEYIS than for those who started in the placebo group and were switched to KEVEYIS2*

Flexible dosing allows for an individualized treatment approach1

  • KEVEYIS can be titrated up or down at weekly intervals based on response1

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).

*The double-blind phase (N=65) was followed by a 1-year, open-label extension phase (N=58) in which all participants received KEVEYIS. Outcomes such as weekly attack rate, severity-weighted attack rate, and total attack duration per week (from weeks 9-61) were assessed. Adverse events and other safety outcomes were also assessed.2

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 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(15):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.