Modafinil is used to treat excessive sleepiness caused by narcolepsy (a condition that causes excessive daytime sleepiness) or shift work sleep disorder (sleepiness during scheduled waking hours and difficulty falling asleep or staying asleep during scheduled sleeping hours in people who work at night or on rotating shifts). Modafinil is also used along with breathing devices or other treatments to prevent excessive sleepiness caused by obstructive sleep apnea/hypopnea syndrome (OSAHS; a sleep disorder in which the patient briefly stops breathing or breathes shallowly many times during sleep and therefore doesn't get enough restful sleep). Modafinil is in a class of medications called wakefulness promoting agents. It works by changing the amounts of certain natural substances in the area of the brain that controls sleep and wakefulness.

Modafinil comes as a tablet to take by mouth. It is usually taken once a day with or without food. If you are taking modafinil to treat narcolepsy or OSAHS, you will probably take it in the morning. If you are taking modafinil to treat shift work sleep disorder, you will probably take it 1 hour before the beginning of your work shift. Take modafinil at the same time every day. Do not change the time of day that you take modafinil without talking to your doctor. Talk to your doctor if your work shift does not begin at the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take modafinil exactly as directed.

Modafinil may be habit-forming. Do not take a larger dose, take it more often, or take it for a longer period of time than prescribed by your doctor.

Modafinil may decrease your sleepiness, but it will not cure your sleep disorder. Continue to take modafinil even if you feel well-rested. Do not stop taking modafinil without talking to your doctor.

Modafinil should not be used in place of getting enough sleep. Follow your doctor's advice about good sleep habits. Continue to use any breathing devices or other treatments that your doctor has prescribed to treat your condition, especially if you have OSAHS.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking modafinil,

• tell your doctor and pharmacist if you are allergic to modafinil, armodafinil (Nuvigil), or any other medications.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking modafinil. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• the following nonprescription or herbal products may interact with modafinil: omeprazole (Prilosec). Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking modafinil. Do not start any of these medications while taking modafinil without discussing with your healthcare provider.
• tell your doctor if you drink or have ever drunk large amounts of alcohol, use or have ever used street drugs, or have overused prescription medications, especially stimulants. Also tell your doctor if you have ever had chest pain, an irregular heartbeat, or other heart problems after taking a stimulant, and if you have or have ever had high blood pressure; a heart attack; chest pain; a mental illness such as depression, mania (frenzied, abnormally excited mood), or psychosis (difficulty thinking clearly, communicating, understanding reality, and behaving appropriately); or heart, liver, or kidney disease.
• you should know that modafinil may decrease the effectiveness of hormonal contraceptives (birth control pills, patches, rings, implants, injections, and intrauterine devices). Use another form of birth control while taking modafinil and for 1 month after you stop taking it. Talk to your doctor about types of birth control that will work for you during and after your treatment with modafinil.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking modafinil, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking modafinil.
• you should know that modafinil may affect your judgment or thinking and may not completely relieve the sleepiness caused by your disorder. Do not drive a car or operate machinery until you know how this medication affects you. If you avoided driving and other dangerous activities because of your sleep disorder, do not start performing these activities again without talking to your doctor even if you feel more alert.
• be aware that you should avoid drinking alcohol while taking modafinil.

Talk to your doctor about eating grapefruit or drinking grapefruit juice while you are taking this medication.

You should skip the missed dose. Wait until the next time you are supposed to take modafinil, and then take your normal dose. If you take modafinil too late in your waking day, you may find it harder to go to sleep. Do not take a double dose to make up for a missed one.

Modafinil may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• dizziness
• difficulty falling asleep or staying asleep
• drowsiness
• nausea
• diarrhea
• constipation
• gas
• heartburn
• loss of appetite
• unusual tastes
• dry mouth
• excessive thirst
• nosebleed
• flushing
• sweating
• tight muscles or difficulty moving
• back pain
• confusion
• uncontrollable shaking of a part of your body
• burning, tingling, or numbness of the skin
• difficulty seeing or eye pain

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• rash
• blisters
• peeling skin
• mouth sores
• hives
• itching
• hoarseness
• difficulty breathing or swallowing
• swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• chest pain
• fast, pounding, or irregular heartbeat
• frenzied, abnormally excited mood
• hallucinating (seeing things or hearing voices that do not exist)
• anxiety
• depression
• thinking about killing or harming yourself

Modafinil may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (https://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Store modafinil in a safe place so that no one else can take it accidentally or on purpose. Keep track of how many tablets are left so you will know if any are missing.

Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines websitehttps://goo.gl/c4Rm4p for more information.

Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location – one that is up and away and out of their sight and reach.https://www.upandaway.org

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online athttps://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• difficulty falling asleep or staying asleep
• agitation
• restlessness
• confusion
• hallucinations (seeing things or hearing voices that do not exist)
• nervousness
• uncontrollable shaking of a part of the body
• fast, slow, or pounding heartbeat
• chest pain
• nausea
• diarrhea

Keep all appointments with your doctor.

Do not let anyone else take your medication. Selling or giving away modafinil is against the law. Ask your pharmacist any questions you have about refilling your prescription.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

• Provigil^®