According to the American Academy of Sleep Medicine Report and the European Federation of the Neurological Societies, amphetamine, methamphetamine, dextroamphetamine, and methylphenidate can effectively treat daytime sleepiness associated with narcolepsy. These medications have a long-standing history of effectiveness in clinical practice. However, there is limited information available regarding their benefit-to-risk ratio. According to a 2015 review article, lisdexamfetamine (Vyvanse) is used off-label because of its recognized utility in managing daytime sleepiness symptoms. However, the societal guidelines did not offer a specific recommendation regarding the specific use of this medication for the management of narcolepsy. [1], [2], [3]
A 2020 case series reported use of lisdexamfetamine in the management of narcolepsy based on experience from five narcoleptic patients in Brazil. Each patient received individualized doses and durations of treatment to help manage excessive daytime sleepiness (EDS) and weight control; weight gain is a common complication in narcoleptic patients, sometimes resulting in increased comorbidities such as metabolic syndrome and cardiovascular risk. Four of the included patients were women, and one was male, ranging in age from 22 to 51 years. Patients met the International Classification of Sleep Disorders, 3rd edition (ICSD-3) criteria for narcolepsy, characterized by an average sleep latency of ≤ 8 minutes and presence of two or more episodes of sleep-onset rapid eye movement (REM) periods. All patients were treated with lisdexamfetamine due to refractory EDS despite treatment with stable doses of methylphenidate or modafinil for at least 3 months. The duration of lisdexamfetamine therapy ranged from 2 to 20 months, with a median of 3 months. The most commonly utilized dosage was 50 mg/day, but one patient was administered 30 mg/day. This particular patient (see Patient 4 on Table 1) experienced the most limited decrease in EDS per the Epworth Sleepiness Scale (ESS). Overall, mean ESS scores decreased from 18.2 to 10.8 after at least 8 weeks of lisdexamfetamine treatment. All patients reported reduced appetite, and four of five reported weight loss. Overall, lisdexamfetamine was concluded to be well tolerated and successful for management of EDS and weight. [4]