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).
Headache, nausea, nervousness, dizziness, or difficulty sleeping may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Remember that your doctor has prescribed this medication because he or she 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.
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).