Transcript 門診案例討論

門診案例討論~
Methylphenidate Use in Narcolepsy
藥師:郭子瑋
日期:95.06.20
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Narcolepsy (1)
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NARCOLEPSY is a neurological disorder that effects
the regulation of sleep and wakefulness. The primary
symptom is excessive daytime sleepiness.

These attacks can last for less than 30 minutes to as
long as several hours (Campbell, 1981).
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Approximately 70% of the patients with narcolepsy
also experience CATAPLEXY during the day (Zarcone,
1973).
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Narcolepsy (2)
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Cataplexy is related to REM sleep.
There are two parts to REM sleep:
1) dreaming with rapid eye movement, and
2) loss of muscle tone. Usually triggered by emotions
(anger, laughter, surprise, fear), patients with cataplexy
go directly into REM sleep, lose muscle tone, but
remain fully conscious. These daytime attacks can last
from several seconds to several minutes (Campbell,
1981).
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Narcolepsy Syndrome

Patients with the narcolepsy syndrome may also
exhibit other symptoms.

These include AUTOMATIC BEHAVIOR, SLEEP
PARALYSIS, HYPNAGOGIC HALLUCINATIONS, and
SLEEP DISTURBANCES.
Automatic behavior is described as lack of awareness
when performing routine tasks (Campbell, 1981).
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Clinical findings
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Clinical findings
Sleep attacks, cataplexy, hypnagogic hallucinations,
sleep paralysis, family history of condition
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Interpretation
Irresistible episodes of daytime onset of sleep
and motor paralysis
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Methylphenidate use in Narcolepsy (1)
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Methylphenidate (10 to 60 milligrams/day) is
indicated for the treatment of narcolepsy in adults and
children.
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It has been shown to improve performance and
ability to stay awake
(Prod Info RITALIN(R) oral tablet, RITALIN-SR(R) oral tablet,
2004; Francisco & Ivanhoe, 1996; Mitler et al, 1987a; Mitler et
al, 1986c; Honda et al, 1979a).
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Methylphenidate use in Narcolepsy (2)
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Summary:
- Methylphenidate is effective for the treatment of narcolepsy in
adults and children 6 years and over
- Methylphenidate improves
performance and ability to stay awake
- Methylphenidate has been
used for various diseases which exhibit hypersomnia as a
prominent clinical feature
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Methylphenidate --Mechanism of action/Effect:

Central nervous system (CNS) stimulant—Although
the primary mechanism is largely unknown , the effects
of methylphenidate appear to be mediated by blockage of
the reuptake mechanism of dopaminergic neurons.
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In narcolepsy, methylphenidate appears to act at the
cerebral cortex and subcortical structures, including the
thalamus, to produce CNS stimulation, resulting in
increased motor activity, increased mental alertness,
diminished sense of fatigue, brighter spirits, and mild euphoria.
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Dosage of Methylphenidate

Narcolepsy:
Adults~
immediate release, 10-60 mg/day ORALLY divided 2
to 3 times daily, preferably 30-45 min before meals
max:60mg/day
(Food may increase oral absorption )
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Pharmacodynamic of Methylphenidate

onset: immediate release tablet ~2hrs
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duration: 3-6hrs
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absorption: readily
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half-life: 2-4hrs
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time to peak: 6-8hrs
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Conclusion
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Narcolepsy FDA Labeled Indication
Overview
Adult
Pediatric
FDA Approval
yes
yes (age 6 years and older)
Efficacy
Effective
Effective
Recommendation
Class IIa
Class IIa
Strength of Evidence
Category B
Category B
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