Adrafinil is a eugeroic that was formerly used in France to promote alertness, attention, wakefulness, positive mood, and other parameters, particularly in the elderly. It was also used off-label by individuals who wished to avoid fatigue, such as night workers or others who needed to stay awake and alert for long periods of time. Additionally, "adrafinil is known to a larger nonscientific audience, where it is considered to be a nootropic agent." Adrafinil is a prodrug; it is primarily metabolized in vivo to modafinil, resulting in very similar pharmacological effects. Unlike modafinil, however, it takes time for the metabolite to accumulate to active levels in the bloodstream. Effects usually are apparent within 45–60 minutes when taken orally on an empty stomach. Adrafinil was marketed in France under the trade name Olmifon until September 2011 when it was voluntarily discontinued.
Pharmacology
Pharmacodynamics
Because α1-adrenergic receptor antagonists were found to block effects of adrafinil and modafinil in animals, "most investigators assume that adrafinil and modafinil both serve as α1-adrenergic receptor agonists." However, adrafinil and modafinil have not been found to bind to the α1-adrenergic receptor and they lack peripheralsympathomimeticside effects associated with activation of this receptor; hence, the evidence in support of this hypothesis is weak, and other mechanisms are probable. Modafinil was subsequently screened at a variety of targets in 2009 and was found to act as a weak, atypical blocker of the dopamine transporter, and this action may explain some or all of its pharmacological effects. Relative to adrafinil, modafinil possesses greater specificity in its action, lacking or having a reduced incidence of many of the common side effects of the former. There is a case report of two patients that adrafinil may increase interest in sex. A case report of adrafinil-induced orofacial dyskinesia exists. Reports of this side effect also exist for modafinil.
Pharmacokinetics
In addition to modafinil, adrafinil also produces modafinil acid and modafinil sulfone as metabolites, which form from metabolic modification of modafinil.
History
Adrafinil was discovered in 1974 by two chemists working for the French pharmaceutical companyLaboratoires Lafon who were screening compounds in search of analgesics. Pharmacological studies of adrafinil instead revealed psychostimulant-like effects such as hyperactivity and wakefulness in animals. The substance was first tested in humans, specifically for the treatment of narcolepsy, in 1977–1978. Introduced by Lafon, it reached the market in France in 1984, and for the treatment of narcolepsy in 1985. In 1976, two years after the discovery of adrafinil, modafinil, its active metabolite, was discovered. Modafinil appeared to be more potent than adrafinil in animal studies, and was selected for further clinical development, with both adrafinil and modafinil eventually reaching the market. Modafinil was first approved in France in 1994, and then in the United States in 1998. Lafon was acquired by Cephalonin 2001. As of September 2011, Cephalon has discontinued Olmifon, its adrafinil product, while modafinil continues to be marketed.
In 2005 a Medical Classification Committee in New Zealand recommended to MEDSAFE NZ that adrafinil be classified as a prescription medicine due to risks of it being used as a party drug. At that time adrafinil was not scheduled in New Zealand.
Research
In a clinical trial with clomipramine and placebo as active comparators, adrafinil showed efficacy in the treatment of depression. In contrast to clomipramine however, adrafinil was well tolerated, and showed greater improvement in psychomotor retardation in comparison. As such, "further investigations of the antidepressive effects of adrafinil are warranted."
