There are multiple US Food and Drug Administration (FDA) approved medications for narcolepsy and none for IH; medications for narcolepsy are frequently extended to off-label use in IH. Modafinil, a non-amphetamine, wakefulness-promoting agent, is considered standard therapy for EDS in narcolepsy by the American Academy of Sleep Medicine (AASM) (Table 4).93 A meta-analysis of 1,054 patients with narcolepsy demonstrated that modafinil (200-600 mg/d) improved EDS relative to placebo, decreasing ESS by 2.73 points (95% CI, −3.39 to −2.08), increasing MSL on MSLT by 1.11 min (95% CI, 0.55-1.66), and increasing MSL on the MWT by 2.82 min (95% CI, 2.4-3.24).102 Although both once-daily (morning) dosing and bid (morning and midday) dosing have been evaluated in randomized controlled trials (RCTs), split-dose regimens of modafinil taken bid appear more effective at controlling symptoms into the evening than single morning dosing.103-105 Despite published use of dosages up to 600 mg/d,102,106 the FDA-listed maximum dose in adults is 400 mg. Armodafinil, the longer half-life enantiomer of racemic modafinil, also significantly increases MSL on MWT compared with placebo in narcolepsy.107 Armodafinil is typically dosed once daily (in the morning). Modafinil and armodafinil are also FDA-approved for the treatment of EDS in OSA syndrome and shift-work sleep disorder. Use of modafinil for IH has been based, until recently, on expert consensus,93 but appears to have similar treatment benefit in IH and narcolepsy with cataplexy in clinical use (ESS change, −2.6 ± 5.1 in IH vs −3 ± 5.1 in narcolepsy).108 In the first published RCT for EDS to include patients with IH, modafinil enhanced driving performance, increased sleep latency on MWT, and decreased subjective sleepiness compared with placebo.109 Advantages of modafinil/armodafinil over traditional stimulants include low abuse potential and a generally better side effect profile. They are, however, associated with headache, nausea, and anxiety, which sometimes abate over time. Postmarketing data revealed rare cases of serious or life-threatening rash (Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug rash with eosinophilia and systemic symptoms).110 Although these medications are not FDA approved for pediatric use, they are used off-label in this population.106 Their interaction with oral contraception (decreasing contraception efficacy) is important to consider in women of childbearing potential.