Celebrating 10 years of PPP Support! See how we ensure you never walk alone here.

What is
Primary Periodic Paralysis?

Learn about this rare and progressive genetic condition
— and the path to diagnosis.

PPP overview

Primary Periodic Paralysis (PPP) is a group of rare, channelopathies that manifest as recurrent attacks of muscle weakness or temporary paralysis often precipitated by triggers.1

Only 4,000 to 5,000 people in the U.S. are diagnosed with PPP.2

As a physician, you can treat and manage Primary Periodic Paralysis. While PPP is rare,
you’re in a unique position to make an impact on someone’s life.

PPP can lead to Permanent Muscle Weakness3

Over time, PPP may lead to Permanent Muscle Weakness (PMW), constant weakness that can occur independently of attacks and becomes more likely in the 5th and 6th decades of life. PMW occurs when the muscle is replaced by fibrous tissue and fat. In order to delay the fatty muscle replacement, it’s been suggested that continuous treatment may be needed.

People with PMW often require mobility aids for daily activities, such as a cane, walker or wheelchair.

PPP subtypes

There are several subtypes of PPP with varying prevalence. The subtypes can be distinguished by the differences in gene mutations, serum potassium levels during an attack of muscle weakness, and duration of episodes.1,4.5

Most common:

Hypokalemic (~1 in 100,000)1,4,5

  • Typically manifests as attacks of weakness that can last for hours
  • During attacks, potassium levels decrease due to potassium shifting from the bloodstream to the skeletal muscle

Hyperkalemic (~1 in 200,000)1,4-6

  • Typically manifests as attacks of weakness that can last for minutes to hours
  • During attacks, potassium levels are elevated due to potassium shifting from the muscle to the bloodstream. Sometimes serum potassium levels can remain normal

Least common:

Paramyotonia Congenita (<1 in 100,000)6,7

  • Typically manifests as sustained muscle tensing that prevents muscles from relaxing. Attacks can last for hours
  • During attacks, potassium levels in the bloodstream can be elevated or normal

Andersen-Tawil Syndrome (ATS) (1 in 1 million)1*

  • Typically manifests as attacks of weakness that can last for hours
  • During attacks, potassium levels in the bloodstream can be high, low, or normal
  • Characteristics of ATS include distinctive skeletal features and cardiac abnormalities such as ventricular arrhythmias, prolonged QT interval, and prominent U waves

*Patients with ATS were not included in clinical trials for KEVEYIS.

What triggers PPP attacks?1,6

Primary periodic paralysis (PPP) triggers can vary from one patient to the next and depend on the type of PPP. It’s important to work with your patients and consider their subtype to help identify their individual triggers.


Common triggers include:

  • Foods or beverages high in salt, carbohydrates or potassium
  • Stress or fatigue
  • Exposure to cold temperatures or cold air
  • Periods of inactivity
  • Resting after exercise

PPP attacks: What to look for

Signs and symptoms (attacks) of PPP are often nonspecific and may have varying clinical presentations among patients.

Attacks range in severity6*

In a study of patients with hyperkalemic periodic paralysis surveyed about their disease:
  • 43.3% said most of their attacks were mild (defined as “some limitations on mobility, others would notice I am in an attack”).
  • 15.6% said their attacks were either severe (defined as “can speak, cannot move at all, can call for help”) or very severe (defined as “cannot speak, cannot call for help”).

Attacks range in frequency3†

  • In this survey, attack frequency was 59% weekly, 28% daily and no attacks in 11%.
  • As patients age, the frequency of attacks may either increase or decrease. In about two-thirds of patients in one study, there was no change in frequency.

Patients with PPP often report6*

  • Attacks often occur in the morning.
  • Muscle weakness due to rest after exercise.
  • Requiring support from a family member or cane to walk during an episode.
  • Difficulty breathing during attacks.

*Based on a survey of 137 adults (>18 years of age) with a diagnosis of hyperkalemic PPP and a genetic diagnosis. Percentages are based on the total number of respondents who answered a given question.

†Based on a survey of 66 self-selected patients over the age of 40 years with a clinical diagnosis of PPP who sought support via the internet.

Certain symptoms that have reportedly appeared after an attack include6:

Learn more about symptoms and triggers in the PPP Disease Education brochure.

Clumsiness

Palpitations

Weakness

Extreme fatigue

Pain

PATIENT IMPACT

Learn more about PPP’s impact on patient lives

PPP can have a significant physical and emotional impact on patients’ lives.1,6 Fear of PPP episodes can cause stress, work and personal life challenges, and social anxiety.
The burden of PPP attacks is not only physical:
Living with PPP can be stressful, and since stress can trigger attacks, it may compound the problem.6

Get helpful information on PPP, from diagnosis to treatment

The Diagnostic Journey

Impact on a PPP Patient's Life

Management and Treatment

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Help patients
with PPP

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By submitting this form, I give permission for a Xeris Pharmaceuticals® representative to contact me by the following methods, but not limited to: phone, email, or text message. I understand I am giving Xeris Pharmaceuticals, Inc., its affiliates, and business partners permission to use the personal information provided in this registration form to contact me by the following methods, but not limited to, mail, email, telephone call or in-person about disease and product information, disease or product-related events, support services, market research, and to share promotional and marketing information. By submitting this form, I consent to these uses and am confirming that I have read and agree to the Xeris Pharmaceuticals Terms of Use and Privacy Statement.

References

  1. Statland JM, Fontaine B, Hanna MG, et al. Review of the diagnosis and treatment of periodic paralysis. Muscle Nerve. 2018;57:522-530.
  2. Data on file. Chicago, IL: Xeris Pharmaceuticals, Inc.
  3. 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.
  4. Cannon SC. Channelopathies of skeletal muscle excitability. Compr Physiol. 2015;5:761-790.
  5. Ralph J, Ptacek L. Muscle channelopathies: periodic paralyses and nondystrophic myotonias. In: Rosenberg RN, Pascual JM, eds. Rosenberg’s Molecular and Genetic Basis of Neurological and Psychiatric Disease. 5th ed. Elsevier; 2015:1177- 1189.
  6. 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;260:2606-2613.
  7. Paramyotonia congenita. MedlinePlus. Updated August 1, 2015. Accessed June 26, 2025. https://medlineplus.gov/genetics/condition/paramyotonia-congenita/

Find answers

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Get customized support for your KEVEYIS journey. Simply fill out the information and a Patient Access Manager will contact you. They will walk you through the entire process, from diagnosis to treatment and beyond.

By submitting this form, I understand I am giving Xeris Pharmaceuticals, Inc., its affiliates, and business partners permission to use the personal information provided in this registration form to contact me by the following methods, but not limited to: mail, email, telephone call or in-person about disease and product information, disease or product-related events, support services, market research, and to share promotional and marketing information. By submitting this form, I consent to these uses and am confirming that I have read and agree to the Xeris Pharmaceuticals® Terms of Use and Privacy Statement. I understand I can unsubscribe by clicking on the unsubscribe link in future communications or by sending a letter with my full contact information (eg, name, address, email, phone, etc) to Xeris CareConnection™ Patient Support Services, 1375 W Fulton Street, Suite 1300, Chicago, IL 60607.

Celebrate with us

Celebrating 10 years of KEVEYIS®

As The Proven Leader for Primary Periodic Paralysis (PPP), we know managing this disease takes more than medication alone. That’s why we’re celebrating 10 years of ensuring you and your patients never walk alone.

Keveyis
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