"my doctor prescribed ultram er 200 for lower back pain and sciatica.  i was taking 1 tablet twice a day.  for 2 or 3 days it seemed to work great.  then i started having side effects.  i had mild dizziness and a slight upset stomach.  i took ultram er for a total of 9 days.  the dizziness became severe, i was lethargic but not able to sleep for more than 2 or 3 hours a night, and the nausea had increased.  i stopped taking ultram er and it took 12 days for the side effects to subside.  the doctor said i had an allergic reaction to this medication."