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.