Modafinil, sold under the brand name Provigil among others, is a central nervous system (CNS) stimulant medication used to treat sleepiness due to narcolepsy, shift work sleep disorder, and obstructive sleep apnea. While it has seen off-label use as a purported cognitive enhancer to improve wakefulness in animal and human studies, the research on its effectiveness for this use is not conclusive. Modafinil is taken by mouth.
Modafinil's side effects include headaches, anxiety, excessive adrenal gland overproduction, and nausea. Serious side effects in high doses include delusions, unfounded beliefs, paranoia, irrational thought, and transient depression, possibly due to its effects on dopamine receptors in the brain, as well as allergic reactions. The amount of medication used should be adjusted in those with kidney problems, as this medication has markedly increased side effects during renal insufficiency.
It is not recommended in those with an arrhythmia, significant hypertension, or left ventricular hypertrophy. Modafinil appears to work by acting on dopamine and modulating the areas of the brain involved with the sleep cycle.
Originally developed in the 1970s by French neuroscientist Michel Jouvet and Lafon Laboratories, Modafinil has been prescribed in France since 1994, and was approved for medical use in the United States in 1998. Its legal status varies by jurisdiction; in the United States it is classified as a schedule IV controlled substance, whereas in the United Kingdom it is a prescription only medication. In some countries no controls apply. It is available as a generic medication. In 2020, modafinil was the 302nd most commonly prescribed medication in the United States, with just over 1,000,000 prescriptions.
Due to modafinil's lack of euphoric effects, it is not considered to be a classical psychostimulant, but rather is classified as a eugeroic (wakefulness-promoting drug).
Modafinil is used primarily for treatment of narcolepsy, shift work sleep disorder, and excessive daytime sleepiness associated with obstructive sleep apnea.