release plus 30mg immediate release for interstitial cystitis & chronic back pain. I've developed a tolerence to the oxcontin. Abuse is not an issue. Methadone scares me. I've never tried any other pain meds & it seems odd to me that methadone is the only option he offers me. I'm also worried about what happens when I develop a tolerence to the methadone? As a chronic pain patient how would I switch back to oxycontin or anything else? I'd really appreciate some advice about all this, thanks in advance.