German scientists synthesized methadone during World War II to make up for a shortage of morphine. Although chemically different than either morphine or heroin, methadone produces many of the same effects. Introduced into the United States in 1947 as an analgesic (Dolophinel), it is mainly used today for the treatment of addiction to opiates, such as such as heroin, OxyContin and Vicodin, but is also used to relieve moderate to severe pain that has not been controlled by non-narcotic pain relievers.
Methadone is available in oral solutions, tablets, and injectable Schedule II formulations, and is almost as effective when administered orally as it is by injection. Its effects can last up to 24 hours, which permits once-a-day oral administration in heroin detoxification and maintenance programs. High-dose methadone can also block the effects of heroin, thereby discouraging the continued use of heroin by addicts under treatment with methadone.
Even when taken according to a doctor’s instructions, methadone can cause constipation, dizziness; drowsiness, dry mouth,; headache, increased sweating, itching, lightheadedness, nausea, pain, redness, or swelling at the injection site, vomiting and weakness.
Chronic administration of methadone results in the development of tolerance and dependence. The withdrawal syndrome develops more slowly and is less severe but more prolonged than that associated with heroin withdrawal. Ironically, methadone used to control narcotic addiction is frequently encountered on the illicit market and has been associated with a number of overdose deaths.
Addicts will continue to use methadone because they are not prepared to experience the withdrawal symptoms that they were originally attempting to escape when they tried to stop abusing opiates, such as such as heroin, OxyContin or Vicodin. Continued abuse of methadone will cause the patient to develop a higher tolerance of it, thus needing a higher dose to achieve the necessary effects. This often results in users becoming stuck in a negative cycle of needing more and taking more, which then leads to a physical dependency on the drug.