Medically Reviewed on 1/19/2023

Generic Name: modafinil

Brand Name: Provigil

Drug Class: Stimulants

What is modafinil, and what is it used for?

Modafinil is an oral prescription medication that is used for improving wakefulness in patients with excessive sleepiness associated with narcolepsy, obstructive sleep apnea (in addition to the treatment of the underlying obstruction), and shift work sleep disorder.

Narcolepsy is a chronic disease of the brain and spinal cord characterized most commonly by a recurrent, uncontrollable desire to sleep. Shift work sleep disorder is a condition in which the normal rhythm of sleep is disturbed, often as a result of working at night. Sleep apnea is a condition where sleep is constantly interrupted at night because of pauses in breathing or shallow breathing usually due to obstruction of the upper airway.

Modafinil is similar to armodafinil (Nuvigil). Like amphetamines, modafinil promotes wakefulness by stimulatIng the brain. The exact mechanism of action of modafinil is unknown. It may work by increasing the amount of dopamine (a chemical neurotransmitter that nerves use to communicate with each other) in the brain by reducing the reuptake of dopamine into nerves. Modafinil was approved by the FDA in December 1998.

What are the side effects of modafinil?

The most common side effects of modafinil include:

What is the dosage for modafinil?

  • The recommended dose is 200 mg once daily not to exceed 400 mg.
  • Modafinil should be administered in the morning for treating narcolepsy or obstructive sleep apnea, and one hour prior to work in those with shift work disorder.
  • Modafinil can be taken with or without food.
  • The 400 mg dose may not be more effective than the 200 mg dose.

What drugs interact with modafinil?

  • Modafinil can decrease or increase the activity of enzymes in the liver that metabolize (eliminate) other drugs. This can result in decreased levels of some drugs that reduce their effectiveness and increased levels of other drugs that leads to their toxicity. Modafinil treatment should be carefully monitored if taken with any of these drugs.
  • Drugs which may have reduced effectiveness if taken with modafinil include cyclosporine (Sandimmune), theophylline, and hormonal contraceptives such as progestin-only or estrogen, and progesterone containing drugs (for example, Micronor, Ortho-Novum 1/50). Alternative hormonal contraceptives or an additional non-drug form of contraception should be considered during treatment with modafinil, and treatment should continue for one month after modafinil therapy ends (since the effects of modafinil on contraceptive hormones may continue for several weeks). The effects of modafinil on hormonal contraceptives occurs if the hormones are taken by mouth, patch, or implant.
  • Drugs that may show increased effects or toxicity if taken with modafinil include warfarin, diazepam (Valium), propranolol (Inderal), imipramine (Tofranil), desipramine (Norpramin), phenytoin (Dilantin) and mephenytoin (Mesantoin).
  • Some other drugs that may increase the effectiveness and/or toxicity of modafinil. These drugs include carbamazepine (Tegretol), phenobarbital, and rifampin (Rifadin).
  • Other drugs, such as ketoconazole (Nizoral) and itraconazole (Sporanox) may reduce the effectiveness of modafinil. Methylphenidate may delay the action of modafinil.
  • The effect of alcohol on modafinil has not been adequately evaluated. Alcohol probably should be avoided while taking modafinil.


Why do we sleep? See Answer

Is modafinil safe to take if I'm pregnant or breastfeeding?

  • There are no adequate studies that assess effects of modafinil in pregnant women. Intrauterine growth retardation and spontaneous abortion have been reported.
  • It is not known if modafinil is excreted in human milk.

What else should I know about modafinil?

What preparations of modafinil are available?
  • Tablets: 100 and 200 mg.
How should I keep modafinil stored?
  • Modafinil should be stored at room temperature, 15 C - 30 C (59 F - 86 F).


Modafinil is a drug prescribed for the treatment of excessive sleepiness associated with narcolepsy, obstructive sleep apnea, and shift work sleep disorder. The most common side effects of modafinil include headache, upper respiratory tract infection, nausea, nervousness, anxiety, and insomnia. Do not take modafinil if pregnant and consult your doctor before taking if breastfeeding.

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See more info: modafinil on RxList
Medically Reviewed on 1/19/2023
Medically reviewed by John P. Cunha, DO, FACOEP; Board Certified Emergency Medicine


FDA Prescribing Information