Excessive daytime sleepiness can interfere with concentration, daily activities, and work performance. It may be associated with conditions such as narcolepsy, sleep apnea, or shift work sleep disorder. Modacare 200 mg contains modafinil, which may help eligible patients remain more alert. Identifying and treating the underlying cause remains an important part of care. A clinician should decide whether modafinil is appropriate and monitor the treatment response.