What is Modvigil for: This medication is an analeptic drug, prescribed for narcolepsy, obstructive sleep apnea and shift work disorder. It works by altering neurotransmitters in the brain. How does Modvigil work: Modvigil fires up the brain to make you more alert. It helps the brain to raise the rate of breathing. How Modvigil 200 should be used: It is available as tablets to take by mouth at bed time. The usual dose is 200-400mg daily as a single morning dose or in 2 divided doses. Common side effects of Modvigil : Sleeplessness, nervousness, aggression, headache, loss of appetite, gastrointestinal disturbances, palpitations and rash. What do I do if I miss a dose Take a missed dose as soon as you think about it. If it is close to the time for your next dose, skip the missed dose and go back to your normal time. Do not take 2 doses at the same time or extra doses. Do not change the dose or stop this drug. Talk with the doctor. What precautions should I take when taking Modvigil :