A 20-year-old college student comes to the office due to falling asleep at inappropriate times. He has an irresistible urge to sleep during the day, and these "naps" occur unpredictably, sometimes at the start of class or during examinations. He sleeps 6-7 hours per night and feels refreshed when he awakens. He also experiences frightening auditory hallucinations before falling asleep. He was recently in a motor vehicle collision after falling asleep at the wheel, which resulted in only a minor sprain of his wrist. He does not use tobacco, alcohol, or illicit drugs. Physical examination is unremarkable. Which of the following is the best treatment for this patient's condition?
Narcolepsy | |
DSM-5 diagnostic criteria |
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Associated features |
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Narcolepsy is a rare neurologic disorder characterized by episodes of irresistible sleep during the day and usually one or more REM sleep–related phenomena such as cataplexy (ie, sudden weakness triggered by strong emotions), hypnagogic/hypnopompic hallucinations (ie, hallucinations while falling asleep or awakening, respectively), and sleep paralysis (ie, physiologic sleep paralysis that persists on awakening/falling asleep). The etiology of narcolepsy is believed to be due to low levels of the stimulatory neurotransmitter orexin (ie, hypocretin), which is involved in maintaining wakefulness and suppressing REM sleep–related phenomena.
Treatment involves the use of agents that promote wakefulness (psychostimulants). Modafinil, a nonamphetamine stimulant, has become the first-line agent because it is effective and well tolerated and its misuse is rare. The mechanism of action is not well described, but modafinil may enhance dopaminergic signaling. Amphetamines are second-line agents due to their sympathomimetic side effects (eg, hypertension, arrhythmia, psychosis) and risk for misuse and dependency.
(Choice A) Carbamazepine is used to treat seizures, bipolar disorder, and trigeminal neuralgia, not narcolepsy.
(Choices B and E) Zolpidem is a nonbenzodiazepine hypnotic used for insomnia. The use of zolpidem or a benzodiazepine (eg, clonazepam) in patients with narcolepsy is relatively contraindicated due to the risk of worsening daytime sedation.
(Choice C) Melatonin is used for treating jet lag and delayed sleep-wake phase syndrome, not narcolepsy.
Educational objective:
Treatment for narcolepsy includes psychostimulants (eg, modafinil) for daytime sleepiness.