Modafinil at a Glance
What Is Modafinil?
Modafinil is a prescription medicine classified as a wakefulness-promoting agent. It is used to improve wakefulness in adults who experience excessive sleepiness associated with certain sleep disorders.
In the United States, the FDA-approved labeling for Provigil (modafinil) lists narcolepsy, obstructive sleep apnea and shift work disorder among its indications. In obstructive sleep apnea, modafinil is used for the associated excessive sleepiness rather than to treat the underlying airway obstruction.
How Does Modafinil Work?
The exact mechanism by which modafinil promotes wakefulness is not completely understood. FDA labeling describes modafinil as having wake-promoting effects, with a pharmacological profile that differs from traditional sympathomimetic stimulants.
Modafinil interacts with several systems involved in wakefulness and brain signaling. Research and regulatory information indicate that its effects are not identical to those of medicines such as amphetamine or methylphenidate.
What Is Modafinil Used For?
Modafinil is used to improve wakefulness in adults with excessive sleepiness associated with specific sleep disorders.
- Narcolepsy: a neurological sleep disorder associated with excessive daytime sleepiness.
- Obstructive sleep apnea: modafinil may be used for persistent excessive sleepiness associated with OSA, alongside treatment for the underlying condition.
- Shift work disorder: excessive sleepiness associated with working during normal sleeping hours.
The approved uses and prescribing requirements can vary between countries. Always refer to the medicine's approved local labeling and advice from a healthcare professional.
Modafinil Dosage
The appropriate dose depends on the medical condition being treated, the individual patient and other factors. Dosage should be determined by the prescribing healthcare professional.
FDA labeling for Provigil lists 100 mg and 200 mg tablets and specifies different dosing schedules depending on the approved indication. This does not mean those doses are appropriate for every person.
Do not increase the dose, take it more frequently or use modafinil for longer than prescribed.
Modafinil vs Armodafinil
Modafinil and armodafinil are related wakefulness-promoting medicines. Armodafinil is the R-enantiomer of modafinil, while modafinil contains both R- and S-enantiomers.
Both medicines are used for excessive sleepiness associated with narcolepsy, obstructive sleep apnea and shift work disorder. They are prescription medicines and should not be treated as interchangeable without professional advice.
Learn more in our Modafinil vs Armodafinil guide .
Is Modafinil Safe?
Like any prescription medicine, modafinil can cause adverse effects and may not be appropriate for everyone. Safety depends on individual medical history, other medicines and how the medicine is used.
Before taking modafinil, tell your healthcare professional about prescription medicines, non-prescription medicines, supplements and herbal products you use. Modafinil can interact with other medicines.
MedlinePlus also notes that modafinil can reduce the effectiveness of hormonal contraceptives during treatment and for one month after stopping it.
Common Side Effects
Reported side effects can include:
- Headache
- Dizziness
- Nausea
- Difficulty sleeping
- Diarrhea
- Dry mouth
- Loss of appetite
- Back pain
This list is not complete. Consult the medicine's prescribing information or speak with a healthcare professional for a complete discussion of adverse effects.
Serious Safety Warnings
FDA labeling warns about potentially serious reactions, including severe skin reactions, angioedema or anaphylaxis, multi-organ hypersensitivity reactions and psychiatric symptoms.
Seek urgent medical attention for symptoms such as a serious rash, blistering or peeling skin, swelling of the face or throat, difficulty breathing, chest pain or significant psychiatric symptoms.
Modafinil Interactions
Modafinil can affect how some other medicines work. Patients should provide their healthcare professional with a complete list of prescription medicines, over-the-counter medicines, vitamins and supplements.
MedlinePlus specifically advises discussing medicines such as omeprazole with a healthcare professional and notes an interaction with hormonal contraceptives.
Modafinil and Alcohol
Patients should discuss alcohol use with their healthcare professional. MedlinePlus advises avoiding alcohol while taking modafinil.
Is Modafinil Habit-Forming?
Modafinil is a controlled prescription medicine in the United States. MedlinePlus warns that it may be habit-forming and advises patients not to take more than prescribed or use it more frequently or for longer than directed.
Modafinil and Driving
Modafinil may reduce sleepiness, but it does not necessarily eliminate impairment associated with a sleep disorder. Patients should not drive or operate machinery until they know how the medicine affects them and have discussed appropriate activity with their healthcare professional.
