Methadone if taken for long periods and at large doses can lead to a very strong long withdrawal period.  Compared to other opiates in which the withdrawal period is a week to ten days, heavy methadone users can expect not to recover for up to 5 or 6 weeks.  So don't use methadone any longer than needed.  If the treatment takes you on a long term course then be sure that the doctor knows of thos long duration of recovery.  If not you could get into a position where the doctor may change drugs or stop methadone suddenly.  According to most medical books withdrawal from opiate addiction should be treated in the hospital. 

Symptoms:

When the time comes not having the drug to take early on the fist day without one can start getting flu like symptoms.  Pain thru -out the body, runny nose, sneezing, faver, insomnia, diarrhea, unable to concentrate, restlessness, anxiety, grouchyness.

If one goes into the second or third day and are left without treatment or not consuming an opiate (pain pill, shoot up) things get worse.  You get musle spasms, nausea, worst case of diarrhea, vomiting, severe backache, stomach pains, hodt and cold flashes, insomnia, intestinal spasms, repetitive sneezing, blood pressure rise, bone and muscle pain, you get intolerant of life, feelings of suicide along with wanting to jump out of your skin.

Using Methadone for getting High:

All narcotics have the tendency to give the user a euphoric feeling in some way or another.  Everone is different.  One person may enjoy the feeling that one drug will give them while another person will not.  One person may have very little tolerance to a drug where anothe rperson will not have any tolerance at all.  This is how overdosages come into play.  If you use pain relievers to get high do not use Methadone.  If you take Methadone whule using other opiates (Percocet, Vicodin, Morphine etc) it will keep you from getting high on those types of opiates causing you to take more and more of both.

If you take more and more to get high then you may overdose.  Leave Methadone for people who need it.