I think methadone could potentially be a really good option for pain management, but it depends on the patient and the pain, and all the ins and outs of both. It is a strong synthetic opioid agonist with a very long half-life and some NMDA-antagonistic properties (I think?). It is quite sedating, and will help with insomnia assosciated with pain. It is quite potent mg per mg, and will jack up your tolerance to other opioids. It isn't terribly euphoric by general opinion, but that is often reported by those who have had experience with IV heroin and are on methadone maintenance. Some say it is euphoric. I have never tried it, I don't know. It does seem to be a bit more dangerouss opioid esp. when combined with other CNS depressants like benzos. It takes a good while to reach full effect after dosing (sometimes several hours), which can lead to excessive and potentially dangerous re-dosing. If you have gone through other opioids with less success, it may be a good option. No harm in giving it a short trial, I suppose.