I think the pain is the result of what the disease is doing to you. Pain killing drugs are not a way of extending life - they don’t ‘fix’ anything except pain. They simply make what’s left of life tolerable.
I think it would be the height of cruelty to forbid them to someone dying, and the height of stupidity to forego them.
I believe that most people are not really afraid of dying - they’re afraid of pain.
I wasn’t thinking of anyone else but the pain receiver making that decision. I would think more pronounced pain would shorten the period one was exposed to pain.