The following information may help to address your question:
Idiopathic hypersomnolence is excessive sleeping (hypersomnia) without an obvious cause. It is different from narcolepsy in that idiopathic hypersomnia does not involve suddenly falling asleep or losing muscle control associated with strong emotions (cataplexy). Symptoms often develop slowly during adolescence or young adulthood and may include daytime naps that do not relieve drowsiness, difficulty waking from a long sleep, increased need for sleep during the day, and increased sleep time (up to 14 - 18 hours per day). Other symptoms may include anxiety, feeling irritated, low energy, restlessness, slow thinking or speech, loss of appetite, and memory difficulty.
Because the underlying cause of idiopathic hypersomnia is unknown, treatment remains symptomatic in nature. The American Academy of Sleep Medicine practice parameters state that successful treatment of hypersomnia of central origin requires an accurate diagnosis, individual tailoring of therapy to produce maximum possible return of function, and regular follow-up to monitor response to therapy. Modafinil, sodium oxybate, amphetamine, dextroamphetamine, methylphenidate, and selegiline are effective treatments for excessive sleepiness associated with narcolepsy and primary hypersomnias. These drugs may not work as well for idiopathic hypersomnia as they do for narcolepsy. Scheduled naps can be beneficial to combat sleepiness in these patients.
Important lifestyle changes that can help ease symptoms and prevent injury include:
Modafinil is the first-line treatment for idiopathic hypersomnolence due to its better risk/benefit ratio. This medication has proved clinically useful in the treatment of narcolepsy and other causes of excessive daytime sleepiness such as idiopathic hypersomnolence. It is a psychostimulant that enhances wakefulness and vigilance, but its pharmacological profile is notably different from the amphetamines, methylphenidate (Ritalin), or cocaine. Modafinil is less likely to produce side effects such as jitteriness, anxiety, or excess locomotor activity or lead to a hypersomnolent rebound effect. It is long-acting, the normal elimination half-life of modafinil in humans is between 12-15 hours.
For more information about modafinil, visit the following link to a page from the eMedicine Web site. http://emedicine.medscape.com/article/291699-treatment