"i have been on ambien for about 8 months but i had started to become tolerant to it.  sometimes i would take it and it would knock me out other times i can take it and still be wide awake until 4am.  my doctor recommended that i try ambien cr but my insurance won&#039;t approve it until i&#039;ve tried lunesta.  what a waste of time!!  it literally had no effect on me whatsoever.  tylenol pm would have done a better job!  i followed the instructions to the tee, didn&#039;t eat a fatty meal and took it on an empty stomach.  has anyone else had this result?  i need to switch back to ambien!"