Hi guys! I have a lot of chronic pain problems with my knee, I had surgery on it a while ago, it has arthritis in it now, it bothers me everyday, I have herniated discs in my lower back and and problems with my left ankle. I have been on all sorts of meds in the past, including vicodin and percocet. My orthopedic Dr. told me before I could mix tylenol with advil and it would equal a pain pill without the narcotic effect. I don't remember how many of each to take and how many hours apart to take each of them. Is this safe? I would rather take these then go back on pain meds! Thanks! :)