Blackhawk,
My PM doc wants to rotate meds since I have been on methadone for 12 years (that and he said all the big PMCs are going to stop writing methadone for some reason: he didn't say.) So, I have been researching alternatives and I found levorphanol - inherently long acting (similar to methadone), very mild "dope-head", no constipation, very small doses (1-2mg q 6-8hrs.) Sounds like a great chronic pain med and so say the patient reviews I have found on it. Hits receptors somewhat differently than most opioids, so low cross tolerance as well.
I am going to ask my PM about it. I don't know why it isn't used more??? Extreme potency is the only thing I can think of. Its been around a loooong time too, so it shouldn't be that expensive.
SeaDoc