"i have been using ambien for several years and i seem to have built a tolerance so that i am no longer falling asleep nor staying asleep.  (note:  i have used both ambien and ambien cr).  i was on a &quot;local&quot; trip and had forgotten my ambien, so i asked my dr if she had samples of anything that would help me sleep.  she gave me silenor samples.  while i was extremely happy with the sleep, i did wake up &quot;hungover&quot; and had a hard time getting moving.  i also experienced very real hallucinations.  don&#039;t know if they will lessen with use, but i am going to ask for a months supply to see if it works out after an adjustment period."