I have been taking Percocet 10/325 for a little over 7yrs due to a back injury. I have had previous surgeries on my back. I have nerve damage in both legs and extreme pain in my back, which limits my mobility. My doctor has prescribed 6 pills a day, to control the pain. I am also on Neurotin 800mg taking 3pills at bedtime. And recently I have been given sleeping meds as well. It seems as if the medication is not working as well anymore. Is my body building up a tolerance or should I be taking a stronger medication?