Drug for wakefulness and alertness
A eugeroic, or eugregoric, is a type of drug that increases wakefulness. The term has been used inconsistently and in multiple ways in the scientific literature, either to refer specifically to modafinil-type wakefulness-promoting agents or to refer to wakefulness-promoting agents generally. It was first introduced in the French literature in 1987 as a descriptor for modafinil-like wakefulness-promoting drugs and for purposes of distinguishing such drugs from psychostimulants. However, the term "eugeroic" has not been widely adopted in the literature, and instead the term "wakefulness-promoting agent" (and variations thereof) has been more widely used, both for modafinil-type drugs and other agents.
Eugeroics, in the sense of modafinil-type wakefulness promoting agents, include modafinil itself, armodafinil, and adrafinil, among others. They are medically indicated for the treatment of certain sleep disorders, including excessive daytime sleepiness (EDS) in narcolepsy or obstructive sleep apnea (OSA). Eugeroics are also often prescribed off-label for the treatment of EDS in idiopathic hypersomnia. In contrast to classical psychostimulants, such as amphetamine and methylphenidate, which are also used in the treatment of these disorders, eugeroics typically do not produce euphoria, and, consequently, have lower misuse potential.
Modafinil and armodafinil are thought to act as selective, weak, atypical dopamine reuptake inhibitors (DRIs). However, additional actions are also possible and have not been ruled out. Adrafinil acts as a prodrug of modafinil and hence shares its mechanism of action. Certain other drugs acting as atypical DRIs with known or potential wakefulness-promoting effects include solriamfetol (also a norepinephrine reuptake inhibitor), vanoxerine, phenylpiracetam, and mesocarb. Other wakefulness-promoting agents act in a variety of other ways.