Primary Periodic Paralysis

Primary Periodic Paralysis (PPP) is rare and not easily diagnosed with an average time from onset of symptoms to correct diagnosis of 26 years.1,2

PPP is very rare, affecting about 4,000 to 5,000 diagnosed individuals in the United States.3

As they age, patients may experience permanent muscle weakness. PPP often interferes with daily activities, as attacks are unpredictable and vary in severity and duration.1,2

In medical terms, PPP is referred to as a group of rare channelopathies manifesting as recurrent attacks of muscle weakness of temporary paralysis often precipitated by triggers.4

Although there are related variants, the most common forms are hyperkalemic and hypokalemic PPP.4

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 misdiagnoses.1

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)1,4
Primary Periodic Paralysis Overview - Acute attacks Acute attacks of flaccid paralysis may be focal or generalized; episodes vary in duration, severity, and frequency4
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 time2,7

*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

Watch our segment on The Balancing Act, featuring Linda Feld, President of the Periodic Paralysis Association and Steve Cannon, MD, PhD, neurologist and professor of physiology at UCLA, as they discuss the symptoms, triggers, misdiagnosis, and genetic testing of PPP.

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 Resource

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.

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. Charles G, Zheng C, Lehmann-Horn F, Jurkat-Rott K, Levitt J. Characterization of hyperkalemic periodic paralysis: a survey of genetically diagnosed individuals. J Neurol. 2013;260(10):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(2):126-133.
  3. Data on file. Feasterville-Trevose, PA: Strongbridge Biopharma; 2017.
  4. Statland JM, Fontaine B, Hanna MG, et al. Review of the diagnosis and treatment of periodic paralysis. Muscle Nerve. 2018;57(4):522-530.
  5. Cheng C-J, Kuo E, Huang C-L. Extracellular potassium homeostasis: insights from hypokalemic periodic paralysis. Semin Nephrol. 2013;33:237-247.
  6. Cannon SC. Channelopathies of skeletal muscle excitability. Compr Physiol. 2015;5(2):761-790.
  7. Jurkat-Rott K, Weber M-A, Fauler M, et al. K+-dependent paradoxical membrane depolarization and Na+ overload, major and reversible contributors to weakness by ion channel leaks. Proc Natl Acad Sci. 2009;106(10):4036-4041.