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 improve or if it worsens.