Which medication is widely recognized for causing drowsiness?

Xanax is widely recognized for causing drowsiness because it is a benzodiazepine, which is a class of medications primarily used to treat anxiety and panic disorders. Benzodiazepines have a sedative effect on the central nervous system, leading to increased feelings of relaxation and calmness. This sedative property makes drowsiness a common side effect of Xanax, particularly when starting the medication or increasing the dosage.

In contrast, Concerta is a stimulant medication used primarily for attention-deficit hyperactivity disorder (ADHD) and is generally associated with increased alertness rather than drowsiness. Prozac, an antidepressant, can sometimes cause insomnia as a side effect rather than drowsiness, and Toprol, a beta-blocker used for managing high blood pressure and heart conditions, may have fatigue as a side effect, but drowsiness is not its primary characteristic. Therefore, Xanax stands out as the medication most connected with causing drowsiness among the listed options.