Hi. When my generalized RSD flared nothing was helping until pm Dr. put me on methadone. I was told it is 10X stronger than any other narcotic, it does take time to build up in your system, it can cause respiratory depression if put on a too high dose too quickly, if you come off it it takes 2-4weeks to come out of your system(most narcotics clear in a few days) but since it takes long to come out of your system the withdraw is not as bad. I called it my miracle drug I was put on 5mg then up to 10mg/day. I don't like narcotics(I am afraid my body will get use to med and wont work when i need it) so after a few months the Dr. has slowly taken me down. I did have horrible sweats and skin sensativity for a few weeks. My flare has calmed down but it is great to know if pain gets out of control I do have something that will help. I would really do research because I did and never found that you could take methadone as needed its too dangerous. momof4