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Content Update

September 16, 2019

Newly Approved Medication for Narcolepsy with or without Cataplexy: The U.S. FDA approved a medication with novel mechanism of action for narcolepsy treatment. Pitolisant (Wakix), the first selective histamine 3 (H3) receptor inverse agonist, was approved in 2019 for narcolepsy.

The H3 receptor inverse agonist was approved for treating excessive daytime sleepiness (EDS) in narcolepsy in adults because of its hypothesized role in increasing wake-promoting histamine. While other treatments for EDS are available, this is the first treatment with the mechanism of action involving histamine.



Upon completion of the chapter, the reader will be able to:

  1. List the sequelae of undiagnosed or untreated sleep disorders and appreciate the importance of successful treatment of sleep disorders.

  2. State the incidence and prevalence of sleep disorders.

  3. Describe the pathophysiology and characteristic features of the sleep disorders covered in this chapter, including insomnia, narcolepsy, restless legs syndrome (RLS), obstructive sleep apnea (OSA), and parasomnias.

  4. Assess patient sleep complaints, conduct sleep histories, and evaluate sleep studies to recognize daytime and nighttime symptoms and characteristics of common sleep disorders.

  5. Recommend and optimize appropriate sleep hygiene and nonpharmacologic therapies for the management and prevention of sleep disorders.

  6. Recommend and optimize appropriate pharmacotherapy for sleep disorders.

  7. Describe the components of the patient care process to implement and assess safety and efficacy of pharmacotherapy for common sleep disorders.

  8. Educate patients about preventive behavior, appropriate lifestyle modifications, and drug therapy required for effective treatment and control of sleep disorders.


Individuals with normal sleep patterns sleep up to one-third of their lives and spend more time sleeping than in any other single activity. Despite this, our understanding of the full purpose of sleep and the mechanisms regulating sleep homeostasis remains incomplete. Sleep is necessary to enable one to maintain wakefulness and good health. Disruption of normal sleep is a major cause of societal morbidity, lost productivity, and reduced quality of life.1 Sleep disturbances may contribute to the development and progression of comorbid medical conditions.1

Sleep is governed and paced by the suprachiasmic nucleus in the brain that regulates circadian rhythm. Environmental cues and amount of previous sleep also influence sleep on a daily basis. There are two main types of sleep: rapid eye movement (REM) sleep, during which eye movements and dreaming occur but the body is mostly paralyzed, and non–rapid eye movement (NREM) sleep, which consists of four substages (stages 1–4). Stage 1 serves as a transition between wake and sleep. Most of the time being asleep is spent in stage 2 NREM sleep. Stage 3 sleep is referred to as deep sleep, or delta sleep, because prominent delta waves are seen on the electroencephalogram (EEG) during this stage of sleep.

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