It is a vasodilator Modafinil 200 mg is a medicine that helps you stay awake and reduces daytime sleepiness. It is used to treat narcolepsy, obstructive sleep apnea, and shift work disorders. It works by increasing the levels of certain chemicals in your brain, which makes you feel more awake. It can also help you fall asleep at night. It is important to talk to your doctor before taking this...