Other people have already covered the fact that this is a bad idea . But I wanted to address some other things I ran the numbers for you and 12 mg methadone is equivalent to approximately 2025 mg oxycodone spread over 24 hours . Be warned , however , there is a LOT of variance with methadone so this is just an approximation . if you ' ve been having constipation that severe on methadone , there are actually effective treatments now . The first thing to do is use Miralax every day . It is safe to do so . If that is not effective or you have already tried that , there are a couple new medications that came on the market that specifically treat opioid induced constipation . These drugs block the action of opiates in your intestines without causing withdrawal in your brain . If this is why you wanted off methadone , I ' m just trying to let you know that issue can be dealt with effectively . I am on 140 mg and have dealt with it by using Miralax alone , but like I said those other drugs just came on the market if you haven ' t spoken to a physician about this issue recently . Methadone is considered one of , if not the , most effective medication for longterm chronic pain . I see an addiction specialist for therapy , and he also deals with pain patients . We ' ve discussed this issue at length and he believes methadone is often the best drug for chronic , non acute pain . It actually is believed to block pain in a unique way , affecting more than just opiate receptors . The biggest issue for you would be the fact that clinics prescribe methadone for once a day , but for pain use the dose is split in to 3 to 4 doses a day . If you have takehome doses you could split the doses yourself . I hope you will reconsider switching to oxycodone , it is EXTREMELY likely to reignite your addiction .