i am not prescribed to either, but i have heard that it can make you sick. i only took 1/8 of the suboxone, as i am not a hard core opiate addict. i have been on lortab 10's for a few weeks {prescribed} and didn't have any today. so i took 1/8 of a suboxone. i just don't know if that was enough to interfere with the methadone. i really just DO NOT want to get sick.