I can't remember if i have taken xarelto 20mg today ,is it safe to leave until next dose due tomorrow?or take half today just in case i missed a dose

Don't take any today: 20mg is the maximum dose. Safer overall to take your usual dose tomorrow than inadvertently take extra

Don't take extra;err: According to FDA, if a dose of Xarelto missed (ie, you remember that you HAVE NOT taken it), then take a dose as soon as you remember ON SAME DAY & resume your usual dose the next day. If you can't remember, the safest thing to do is to SKIP TODAY & keep track tomorrow (check off a calendar every dose). No need to take 1/2 pill. Overdosing is dangerous & not advised, so err on side of underdosing.