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 group of rare channelopathies manifesting as recurrent attacks of muscle weakness or temporary paralysis often precipitated by triggers.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

PPP often has nonspecific and episodic symptoms that mimic those of more common diseases, resulting in years of diagnostic delays and misdiagnoses1

Average time from onset of symptoms to correct diagnosis is 26 years†2

Primary Periodic Paralysis Overview
Primary Periodic Paralysis Overview - Environmental triggers Typically precipitated by triggers, which vary from patient to patient (ie, foods rich in potassium or carbohydrates, rest after exercise, exposure to cold, and stress)1,10,11
Primary Periodic Paralysis Overview - Acute attacks Acute attacks of flaccid paralysis may be focal or generalized; episodes vary in duration, severity, and frequency1,10
Primary Periodic Paralysis Overview - Symptoms may linger Patients have reported experiencing lingering symptoms after an attack, including weakness, extreme fatigue, muscle pain, and clumsiness1
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

Based on a survey of 66 self-selected patients over the age of 40 years with a clinical diagnosis of Primary Periodic Paralysis who sought support via the Internet.2

Educational Segment on 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.

PPP Online Resources

PavingMyPPPath includes a website focused on PPP and accounts on Facebook, Instagram, and YouTube. Follow PavingMyPPPath on social media for posts related to PPP and to hear from those living with PPP.
Inspire® was created with the belief that patients and caregivers need a safe and secure place to support and connect with one another. The Inspire PPP community is an online support group for patients and caregivers living with PPP where you can post in the community and respond to others.

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. Statland JM, Fontaine B, Hanna MG, et al. Review of the diagnosis and treatment of periodic paralysis. Muscle Nerve. 2018;57:522-530.
  4. Symphony Health 2017, Revised Diagnosed PPP Patient Count Estimate, Feasterville-Trevose, PA: Strongbridge Biopharma DOF-00143.
  5. National Institutes of Health. Hyperkalemic periodic paralysis.
  6. National Institutes of Health. Hypokalemic periodic paralysis.
  7. National Institutes of Health. Anderson-Tawil syndrome.
  8. National Institutes of Health. Potassium-aggravated myotonia.
  9. National Institutes of Health. Paramyotonia congenita.
  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 [package insert]. Feasterville-Trevose, PA: Strongbridge Biopharma.

For accessibility-related questions, comments, or concerns about this digital property, please email [email protected] and we will reply to your message.

© 2021 Strongbridge Biopharma plc
STRONGBRIDGE BIOPHARMA® is a registered trademark of the Strongbridge Biopharma plc. companies, which include Strongbridge Dublin Limited and Strongbridge U.S. Inc.
KEVEYIS® is a registered trademark licensed exclusively in the U.S. to Strongbridge Biopharma plc.
MLR-0010 V20 10/2020

  • Ireland Address:
    Suite 206, Fitzwilliam Hall
    Fitzwilliam Place, Dublin 2, D02 T292
  • U.S. Address:
    900 Northbrook Drive, Suite 200
    Trevose, PA 19053
    United States

Phone: +1 610-254-9200
[email protected]

Privacy Statement
Compliance Program