I recently switched doctors due to insurance purposes. Before I was taking the 15mg roxicodone 4x a day. Now the new doctor that I see has got me on 15mg of MS Contin 2x a day and 10mg of percocet 3x a day. I do not however feel this is helping me because my back and leg pain is worse. I have had 3 back surgeries, the last one being a fusion with the hardware. I have called and spoke with my doctors nurse and she told me instead of taking the ms contin every 12hrs. to take it every 8hrs. and I have done this with no relief! What I am asking is: How long will I have to wait before the meds kick in? Right now if I were to rate this medication I would give it a -0. Please, any help would be appreciated.