A diagnosis of
narcolepsy requires pharmacologic treatment in more than 90% of patients. Wake-promoting compounds are used to treat
excessive daytime sleepiness (EDS), and anticataplectics are used for
cataplexy. The treatment of EDS includes the use of
amphetamine-like
CNS stimulants (such as
dextroamphetamine and
methylphenidate),
modafinil, and its R-enantiomer,
armodafinil. Because of its high safety and low side-effect profiles,
modafinil has become the first-line treatment of choice for EDS associated with
narcolepsy. However, wake-promoting compounds do not improve
cataplexy and dissociated manifestation of REM sleep, and so
antidepressants (monoamine uptake inhibitors) are additionally used for the treatment of
cataplexy and REM sleep abnormalities.
Tricyclic antidepressants potently reduce REM sleep and thus have been used for the treatment of
cataplexy and REM sleep abnormalities, but these have recently been replaced by more selective
serotonin and/or
noradrenaline uptake inhibitors with better side-effect profiles. As
sodium oxybate (the approved formula of γ-hydroxybutyrate in the United States), given at night, improves both EDS and
cataplexy, the number of US patients treated with
sodium oxybate is increasing, while much progress has been made in understanding the modes of action of
amphetamine-like
CNS stimulants.