Opiates are powerful medications with strong mental and physical effects, making them potentially addictive substances. They act on pain receptors in the central nervous system. Opiates such as heroin and morphine work in the same fashion as methadone, which is a substance commonly used in the treatment of patients previously addicted to opiates. As the body is exposed to pain medications of this type, it becomes "used to" the effects of the opiates. When the opiates are taken away, the body withdraws, as it is no longer getting its usual stimulus.
Stopping methadone abruptly can produce the same effects as stopping heroin abruptly. A withdrawal syndrome involving nausea, abdominal pain, diarrhea
, sweating, chills, runny nose, anxiety
, and elevated heart rate among other symptoms can result. For this reason, if a patient and his/her doctor
decide to end methadone treatment, the medication should be tapered off over a long period of time.