I just had reverse shoulder replacement 10 days ago and prescribed oxycondon/ acetaminophen 5-325 2 pills every 4 hrs. I was already on tramadol 50 mg 4x day and gabapentin 100 mg 2x day from pain dr for other problems. I picked up refill today and was told not to mix these. They gave me this in hospital and directions said to continue when I got home. I have already weaned myself on oxy down to 1/2 pill every 6/7 hrs. Now I m confused about combining ? I also take 5 mg ambien and 25 mg norttiptyline at night for many yrs. I am 74 yr old female.