Primary Periodic Paralysis

Primary Periodic Paralysis (PPP) is not easily diagnosed and may often go untreated for many years. PPP often interferes with daily activities as attacks are unpredictable and vary in severity and duration. As they age, patients may experience permanent muscle weakness.1,2

In medical terms, Primary Periodic Paralysis is referred to as a spectrum of chronic genetic, neuromuscular disorders with autosomal dominant inheritance.3

Primary Periodic Paralysis is very rare, affecting about 4,000 to 5,000 diagnosed individuals in the United States.4 Although there are related variants, the most common forms are hyperkalemic and hypokalemic PPP.5-9

Primary Periodic Paralysis Overview

Paralytic attacks result from loss of muscle membrane excitability10 Clinical attacks vary widely2:
  • Daily (28%)
  • Weekly (59%)
Time between disease onset and diagnosis is often delayed and can take more than 20 years1,2
Primary Periodic Paralysis Overview
Primary Periodic Paralysis Overview - Environmental triggers May be precipitated by environmental triggers (ie, foods rich in potassium or carbohydrates, rest after exercise, exposure to cold, and emotional stress)1,10,11
Primary Periodic Paralysis Overview - Acute attacks Acute attacks of flaccid paralysis may be focal or generalized; episodes vary in duration and frequency1,10
Primary Periodic Paralysis Overview - Symptoms may linger Symptoms may linger after an attack resolves (ie, clumsiness, extreme fatigue, weakness, palpitations, and pain)1,12
Primary Periodic Paralysis Overview - Quality of life As they age, some patients may experience permanent muscle weakness, further impacting their quality of life over time2

Educational Segment in Primary Periodic Paralysis

Strongbridge Biopharma sponsored an educational segment about Primary Periodic Paralysis on The Balancing Act, “Behind the Mystery: Rare and Genetic Diseases.” The segment features Linda Feld, Vice President of Periodic Paralysis Association (PPA), and Steve Cannon, MD, PhD, neurologist and professor of physiology at UCLA. A broad range of topics related to Primary Periodic Paralysis are addressed within the segment, including symptoms, triggers, misdiagnosis, and genetic testing.

No-Cost Genetic Testing

Uncovering Periodic Paralysis is a no-cost genetic testing program for those who have episodic muscle weakness or temporary paralysis provoked by common triggers for hyperkalemic or hypokalemic periodic paralysis. To learn more, please visit You can also download the patient brochure or HCP brochure.

An Online PPP Community

The Inspire community is an online support group designed to connect patients and caregivers living with PPP. Members can connect with each other and provide support, as well as share valuable support and information.

The First and Only FDA-Approved Treatment:

KEVEYIS® (dichlorphenamide) 50 mg tablets, an oral medication with twice-daily dosing, is indicated for the treatment of13:
  • Primary hyperkalemic Primary Periodic Paralysis
  • Primary hypokalemic Primary Periodic Paralysis
  • Related variants of Primary Periodic Paralysis

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. Charles G, Zheng C, Lehmann-Horn F, Jurkatt-Rott, Levitt J. Characterization of hyperkalemic periodic paralysis: a survey of genetically diagnosed individuals. J Neurol. 2013;260:2606-2613.
  2. Cavel-Greant D, Lehmann-Horn F, Jurkat-Rott K. The impact of permanent muscle weakness on quality of life in periodic paralysis: a survey of 66 patients. Acta Myol. 2012;31:126-133.
  3. Grieg SL. Dichlorphenamide: a review in primary periodic paralyses. Drugs. 2016;76:501-507.
  4. Data on file. Feasterville-Trevose, PA: Strongbridge Biopharma; 2017.
  5. National Institutes of Health. Hyperkalemic periodic paralysis. Accessed December 5, 2016.
  6. National Institutes of Health. Hypokalemic periodic paralysis. Accessed December 5, 2016.
  7. National Institutes of Health. Anderson-Tawil syndrome. Accessed December 5, 2016.
  8. National Institutes of Health. Potassium-aggravated myotonia. Accessed December 5, 2016.
  9. National Institutes of Health. Paramyotonia congenita. Accessed December 5, 2016.
  10. Cannon SC. Channelopathies of skeletal muscle excitability. Compr Physiol. 2015;5:761-790
  11. Vicart S, Sternberg D, Arzel-Hezode, M, et al. Hypokalemic Periodic Paralysis. NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health. 2014.
  12. Weber F, Jurkat-Rott, Karin, Lehmann-Horn F. Hyperkalemic Periodic Paralysis. NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health. 2016.
  13. KEVEYIS® (dichlorphenamide) [package insert]. Trevose, PA: Strongbridge Biopharma; 2015.

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