I had TKR three weeks ago. Only meds I m taking is Naproxen Sodium (440 mg 2x daily). Is it safe to add acetaminophen to this. Not taken at the same time .... Example 1pm Naproxen, 4pm Acetaminophen, 7pm Naproxen, 4am Acetaminophen, etc. I have taken NO pain meds throughout, but my muscles are so tight this weekend they re causing me major discomfort. (59 y old woman). Thank you.