Methadone is a full agonist while buprenorphene (suboxone,subutex) is a partial antagonist.
Being a apartial antagonist make's buprenorphene espcially good for addiction as it has a ceiling effect.Buprenorphene has the highest affinity to the opiate receptors so once your on a stable dose nothing else (as far as an opiate goes) is going to work.
Buprenorphene is 40 times stronger than
morphine and has been used as a I.V. pain killer for years.I think the usual dose is .2mgs I.V. .
Buprenorphene also has an extremely long half life (36-72 hrs) which also makes it a good choice for addiction recovery.
Methadone is a full agonist just like morphine but many many times stronger.Methadone has a half life of 24-36hrs making it a good pain killer and a good choice for a heavily addicted patient.
Methadone acts differently then say
oxycodone or morphine in that it doesn't hit you fast.It gradually comes up and I believe the peak values are around 6 hours.
Oxycodone and\or morphine are used early in a chronic pain patients case's but eventually due to tolerance these drugs become almost useless after some time.
This is when methadone should be used or
duragesic patch and even the morphine pump.
I can tell you that if you are a chronic pain patient to learn as much as you can about the drugs and the overall class of drugs you're going to be taking for the rest of your life.There is alot of misinformed people out there with good intentions but they really don't know what they are talking about and that can be dangerous.So good luck and I hope you are able to control your chronic pain and have a good quality life......Dave