Most frequently, doctors suggests the patients to cut the 2mg Xanax bars into pieces of four and then use them in order to evade the dependency problem. In very rare cases they do prescribe the 3mg bar. Excess dosage of Xanor or Xanax cause sleepiness too and brings about heaviness in breath. In case you ever find yourself in such a situation, get in touch with your doctor immediately.While you are on Xanax, you have to exercise great caution while working or driving for there is certain amount of sedation that comes along with the usage of this drug. And the situation worsens if one indulges in taking alcohol while on alprazolam.