Modafinil reduces extreme sleepiness due to narcolepsy and other sleep disorders, such as periods of stopped breathing during sleep (obstructive sleep apnea). It is also used to help you stay awake during work hours if you have a work schedule that keeps you from having a normal sleep routine (shift work sleep disorder).

This medication does not cure these sleep disorders and may not get rid of all your sleepiness. Modafinil does not take the place of getting enough sleep. It should not be used to treat tiredness or hold off sleep in people who do not have a sleep disorder.

It is not known how modafinil works to keep you awake. It is thought to work by affecting certain substances in the brain that control the sleep/wake cycle.

Read the Medication Guide provided by your pharmacist before you start using modafinil and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

For narcolepsy, take this medication by mouth with or without food as directed by your doctor, usually once daily in the morning. Or, if your doctor directs you to, the total daily dose of modafinil may be divided into a morning dose and a noon dose.

For obstructive sleep apnea, take this medication by mouth with or without food as directed by your doctor, usually once daily in the morning. Continue your other treatment (such as the CPAP machine, mouth device) unless your doctor tells you to stop.

If you are using modafinil for shift work sleep disorder, take it by mouth with or without food as directed by your doctor, usually once a day 1 hour before you start your work shift.

The dosage is based on your medical condition and response to treatment. Take this medication regularly to get the most benefit from it.

If you suddenly stop using this medication, you may have withdrawal symptoms (such as shaking, sweating, chills, nausea, vomiting, confusion). To help prevent withdrawal, your doctor may lower your dose slowly. Withdrawal is more likely if you have used modafinil for a long time or in high doses. Tell your doctor or pharmacist right away if you have withdrawal.

When this medication is used for a long time, it may not work as well. Talk with your doctor if this medication stops working well.

Though it helps many people, this medication may sometimes cause addiction. This risk may be higher if you have a substance use disorder (such as overuse of or addiction to drugs/alcohol). Take this medication exactly as prescribed to lower the risk of addiction. Ask your doctor or pharmacist for more details.

Tell your doctor if your condition does not get better or if it gets worse.

Headache, nausea, nervousness, dizziness, or difficulty sleeping may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• fast/pounding/irregular heartbeat
• mental/mood changes (such as agitation, confusion, depression, hallucinations, rare thoughts of suicide)

Get medical help right away if you have any very serious side effects, including:

• chest pain

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• fever
• swollen lymph nodes
• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking modafinil, tell your doctor or pharmacist if you are allergic to it; or to armodafinil; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• heart problems (such as enlarged heart, mitral valve problem, chest pain, heart attack, irregular heartbeat)
• heart problems after taking stimulant drugs such as amphetamines (including chest pain, irregular heartbeat)
• high blood pressure
• liver problems
• mental/mood disorders (such as depression, mania, psychosis)
• personal or family history of a substance use disorder (such as overuse of or addiction to drugs/alcohol)

Sleep disorders may reduce your ability to react quickly. Though modafinil helps keep you awake, you still may not be able to safely do things that require quick reactions (such as driving). This drug may also make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using modafinil. Modafinil may harm an unborn baby. Ask about reliable forms of non-hormonal birth control while using this medication and for 2 months after the last dose. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• street drugs (such as methamphetamine, MDMA/"ecstasy")

This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use reliable backup birth control methods while using this medication and for 1 month after the last dose. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well.

Modafinil can speed up the removal of other medications from your body, which may affect how they work. Examples of affected drugs include axitinib, bosutinib, daridorexant, elacestrant, certain products used to treat chronic hepatitis C (asunaprevir, ombitasvir/paritaprevir/ritonavir), mavacamten, quizartinib, revumenib, among others.

Some products have ingredients that could raise your heart rate or blood pressure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products or diet aids).

Caffeine can increase the side effects of this medication. Avoid drinking large amounts of beverages containing caffeine (coffee, tea, colas), eating large amounts of chocolate, or taking nonprescription products that contain caffeine.

Modafinil is very similar to armodafinil. Do not take medications containing armodafinil while using modafinil.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose include: fast/irregular heartbeat, severe restlessness, hallucinations.

Do not share this medication with others. Sharing it is against the law.

Lab and/or medical tests (such as blood pressure, heart rate) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

Follow good sleep habits (such as sleeping in a dark/quiet room, avoiding caffeine close to bedtime) which can help improve your sleep if you have shift work sleep disorder.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up. Do not take missed doses close to bedtime because doing so may make it harder to go to sleep.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.