Can anyone explain to me what Xanax xr are. I know it stands for extended relief, but does it release just a small amount over a longer period of time, these are 1.5 and dont seem to have the immediate relief that xanax 1mg have. Also is it true crushing or dissolving them will rid them of the XR effect? And how long is the XR effect to last, ie over 12 hours, 8 hours or what. Any info would greatly appreciated. Thanks