I occassionally take xanax to make myself fall asleep and I usually take twice the prescribed amount than I would for day-time anxiety release use.I haven't done so in a while so my tolerance may have went down. Last night I set an alarm for 10:30 am but I woke up at 1:00pm instead and it appeared my alarm didn't go off. Is it possible that I woke up and turned the alarm off and fell back asleep without knowing because the of the xanax? I know it can cause blackouts but I didn't think it could happen after you're already passed out.