I Am 71 Yr Old. Have Had 17 Surgeries,3 Rotor

I am 71 yr old. Have had 17 surgeries,3 rotor cuffs....no cartilage in left very little in right. Right knee surgery caused by brown recluse spider bite, venom ate a third of my kneecap, half the tendons and bursa sac removed. 7 various surgeries on both feet. Too long to explain them. My doctor has me on 4 Advils, alternating with 4 Tylenol and 2 Acetaminophen 500 mgs. each. Is there a different regimen that I could be taking fewer pills? I am in extreme pain most of the time.