He was taking tylenol for neuralgia. It harmed his liver so bad he had severe jaundice. He was barely able to walk and was completely unable to speak.
He died at the age of 68.
@Michael - I suspect the downvoting is a reaction to your tone. The certainty with which you prevented your statement, along with its (on-the-surface) appearance of being unrelated to the conversation made it appear as if you had an axe to grind. The downvotes (I hope) were a (misguided) attempt to rectify this behavior.
I bet that a lot of people who downvoted you would have supported your comment if your words were changed a little so the tone came across more clearly. Something like, "I wish there had been an autopsy done on my father, who died of renal failure. He had been advised to take XYZ medication, much of which contained acetaminophen. His autopsy could have supported science that brought awareness of cumulative acetaminophen ingestion."
I am sorry for your loss. Thank you for sharing your experience -- it led me to research acetaminophen toxicity, where I found out that the deaths caused may be greatly underreported due to a variety of factors. (http://www.propublica.org/article/tylenol-mcneil-fda-behind-...)
Better post-mortem data from autopsies in cases like your fathers would go a long ways towards understanding the scope of the problem.
That's what destroyed my father's liver.