Pronunciation: moe-daf’-i-nil
Generic name: modafinil
Brand name: Provigil
Dosage form: oral tablet
Drug class: CNS stimulants

Medically reviewed by Carmen Pope, BPharm. Last updated on Nov 18, 2024.

What is modafinil?

Modafinil promotes wakefulness and is used to treat excessive daytime sleepiness caused by narcolepsy, obstructive sleep apnea (OSA), or shift work sleep (SWS) disorder.

• Modafinil does not treat the underlying disorder, it only makes people feel more awake.
• Modafinil does not take the place of other treatments for narcolepsy or OSA. These should be continued while you are taking modafinil.

Modafinil's exact mechanism of action is unclear. However, it's believed to work by affecting brain chemicals that regulate sleep and wakefulness. While similar to stimulants like amphetamine and methylphenidate, modafinil has a different chemical structure. Modafinil belongs to the drug class called CNS stimulants.

Modafinil is classified as a Schedule IV (4) controlled substance due to its potential for misuse and dependence. Misuse of modafinil is illegal and harmful and you should always keep it in a safe place and never share it with others. Tell your doctor if you have a history of substance abuse.

Modafinil gained FDA approval on December 24, 1998, under the brand name Provigil. Modafinil is available as a generic and under the brand name Provigil.

Nuvigil is a purified version of modafinil (see Nuvigil (armodafinil) vs Provigil (modafinil): How do they compare?).

Modafinil side effects

The most common side effects of modafinil are:

• a headache
• dizziness
• feeling nervous or anxious
• back pain
• nausea
• diarrhea
• an upset stomach
• sleep problems (insomnia)
• poor appetite
• a stuffy nose.

Weight loss is not a recognized side effect of modafinil, although nausea and poor appetite are common side effects of modafinil that may lead to weight loss.

Serious side effects and warnings

You should not use modafinil if you have ever had an allergic reaction or developed a skin rash while taking modafinil, Provigil, armodafinil, or Nuvigil. Angioedema and hypersensitivity reactions (including rash, difficulty swallowing, narrowing of the airways, and hypersensitivity reactions that affect multiple organs) have been reported with medications in the same class as modafinil. Stop taking modafinil and get emergency medical help if you have signs of an allergic reaction to modafinil such as hives (an itchy skin rash), difficulty breathing, or swelling of your face, lips, tongue, or throat.

Modafinil can cause skin reactions that may be severe enough to need treatment in a hospital. Stop taking this medicine and get emergency medical help if you develop any of the following, no matter how minor it appears:

• skin rash or hives, blisters or peeling
• mouth sores, trouble swallowing
• fever, shortness of breath
• swelling in your legs
• dark urine, jaundice (yellowing of the skin or eyes)
• swelling in your face, eyes, lips, tongue, or throat.

Modafinil may impair your thinking or reaction time. Be careful if you drive or do anything that requires you to be alert. Avoid other dangerous activities until you know how this medication will affect your level of wakefulness. Modafinil may not return your level of alertness to what it was before you developed narcolepsy or OSA.

Psychiatric side effects, such as anxiety, confusion, insomnia, depression, or agitation, have been reported in people treated with modafinil. Stop using modafinil and call your doctor at once if you have:

• depression or suicidal thoughts or actions
• anxiety
• hallucinations or unusual thoughts or behavior
• aggression
• being more active or talkative than usual.

Cardiovascular side effects, including chest pain, trouble breathing, uneven heartbeats, shortness of breath, or changes on an ECG have been reported in trials with modafinil. Stop taking modafinil and call your doctor if you have chest pain, trouble breathing, or uneven heartbeats.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Related/similar drugs

Before taking

Do not take modafinil if you have ever had an allergic reaction or skin rash while taking modafinil, Provigil, or armodafinil (Nuvigil).

To make sure modafinil is safe for you, tell your doctor about all your medical conditions, including if you have:

• angina (chest pain)

• cirrhosis or other liver problem

• kidney disease

• high blood pressure, heart disease, or history of heart attack

• a history of mental illness or psychosis

• history of alcoholism or drug addiction.

• are pregnant or intending to become pregnant

• are breastfeeding or intending to breastfeed.

Modafinil is not approved for use by anyone younger than 17 years old.

Pregnancy

Based on animal data, modafinil may harm an unborn baby. There have been no adequate studies in humans. Talk to your healthcare provider about using adequate birth control methods while taking Modafinil, if you are a woman of childbearing potential. Be aware that modafinil can make certain birth control less effective. Hormonal contraception (birth control pills, injections, implants, skin patches, and vaginal rings) may not be effective enough to prevent pregnancy during your treatment and for one month after finishing your treatment. Talk with your doctor about the best methods of birth control to use while taking modafinil.

A pregnancy registry has been established to collect information on the pregnancy outcomes of women exposed to modafinil if they inadvertently become pregnant while taking modafinil. Healthcare providers are encouraged to register pregnant patients, or pregnant women may enroll in the registry by calling 1-866-404-4106 (toll-free).

Breastfeeding

It is not known whether modafinil passes into breast milk or if it could harm a nursing baby.

How should I take modafinil?

Take modafinil exactly as prescribed by your doctor. Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions. Do not take this medicine in larger or smaller amounts or for longer than recommended.

• Modafinil may be habit-forming. Never share modafinil with another person, especially someone with a history of drug abuse or addiction.
• Keep the medication where others cannot reach it. Selling or giving away this medicine is against the law.

Modafinil is usually taken 1 time each day.

• Take modafinil in the morning (when you wake up) if you suffer from daytime sleepiness due to narcolepsy or OSA.
• Take modafinil 1 hour before the start of a work shift if you are taking it to treat work-time sleep disorders.

You may take the tablet with or without food.

Modafinil is usually given for 12 weeks or less.

Call your doctor if you continue to have excessive sleepiness even while taking this medicine.

• Taking modafinil does not take the place of getting enough sleep.

Keep track of the amount of medicine used from each new bottle. Modafinil is a drug of abuse and you should be aware if anyone is using your medicine improperly or without a prescription.

Modafinil for OSA

If you take modafinil to treat sleepiness caused by obstructive sleep apnea, you may also be treated with a continuous positive airway pressure (CPAP) machine.

• This machine is an air pump connected to a mask that gently blows pressurized air into your nose while you sleep. The pump does not breathe for you, but the gentle force of air helps keep your airway open to prevent obstruction.
• Do not stop using your CPAP machine during sleep unless your doctor tells you to. The combination of treatment with CPAP and modafinil may be necessary to best treat your condition.

Modafinil will not cure obstructive sleep apnea or treat its underlying causes. Follow your doctor's instructions about all your other treatments for this disorder.

Modafinil dosage

Usual Adult Dose for Narcolepsy:

• Modafinil 200 mg orally daily in the morning.

Usual Adult Dose for Obstructive Sleep Apnea/Hypopnea Syndrome:

• Modafinil 200 mg orally daily in the morning.

Usual Adult Dose for Shift Work Sleep Disorder:

• Modafinil 200 mg orally daily one hour before the start of the work shift.

Modafinil and ADHD

Modafinil is not FDA-approved for use in children for any medical condition including Attention Deficit Hyperactivity Disorder (ADHD).

Studies on children have shown potential risks outweigh any benefits. Serious skin reactions and behavioral issues have been reported. Other side effects reported when modafinil was given to children with narcolepsy included:

• Tourette’s syndrome
• hostile behavior
• increase in sudden loss of muscle tone and severe muscle weakness
• increase in seeing and hearing things when falling asleep
• increase in suicidal thoughts
• low white blood count
• painful menstrual periods.

What happens if I miss a dose?

Talk with your doctor about what to do if you miss a dose of modafinil.

Do not take a dose of modafinil if you remember your dose but it is almost bedtime or you do not plan to be awake for several hours.

• Skip the missed dose. Do not take extra medicine to make up for the missed dose the next day.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What to avoid

Modafinil may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Avoid other dangerous activities until you know how modafinil will affect your level of wakefulness.

Avoid drinking alcohol while taking modafinil.

What other drugs will affect modafinil?

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Modafinil and certain other medicines may affect each other causing possible serious side effects or affecting the way each other works. Especially tell your healthcare provider if you take:

• Medications that are substrates for CYP3A4/5 (such as contraceptives, cyclosporine, midazolam, and triazolam). These may not be as effective when taken in combination with modafinil
  • Contraceptives in particular may not be as effective while taking modafinil and for one month after discontinuing it.
• Medications that are substrates for CYP2C19 (such as phenytoin, diazepam, propranolol, omeprazole, and clomipramine) may have their effect prolonged by modafinil, leading to an increased risk of side effects or toxicity.
• Warfarin. More frequent monitoring of prothrombin times/INR should be considered whenever modafinil is coadministered with warfarin
• Monoamine oxidase (MAO) inhibitors, such as isocarboxazid, phenelzine, selegiline, and tranylcypromine. Caution should be used when concomitantly administering MAO inhibitors and modafinil.

This is not a complete list of interactions. See the Modafinil Prescribing Information for more information.

Storage

Store modafinil tablets at room temperature away from moisture and heat.

Modafinil ingredients

Active ingredients: modafinil 100 mg or 200 mg

Modafinil is available under the brand name Provigil or as a generic.

Provigil inactive ingredients: croscarmellose sodium, lactose monohydrate, magnesium stearate, microcrystalline cellulose, povidone, and pregelatinized starch.

Provigil is available as modafinil 100 mg and modafinil 200 mg.

Who makes Modafinil?

Cephalon, LLC manufactures modafinil under the brand name Provigil.

Generic modafinil is made by Alembic Pharmaceuticals Inc., Apotex Corp., Aurobinda Pharma Ltd., and many more.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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