Methadone is an example of an opiate agonist, a drug that mimics effects of endorphins that naturally occur in the body. They produce an opiate-like effect by working on the opioid receptor sites.
Opiate agonists are synthetic, designed to stave off cravings and opiate withdrawal. They are not supposed to cause feelings of euphoria or a "high," though these drugs can become habit forming. Opiate agonists can be used in opiate replacement therapy to treat addiction to opiates including heroin and OxyContin.
Opiate Antagonists and Partial Opiate Agonists
To contrast, an opiate antagonist (naloxone, naltrexone) is a drug that replaces opiate agonists at the receptor sites. This drug prevents people from experiencing opiate effects of the agonist drug.
An example of a partial opiate agonist is buprenorphine. This drug is included in medications such as Suboxone and Subutex and helps to manage opiate withdrawal. The withdrawal associated with opiates can be grueling physically, mentally and emotionally. People may find it nearly impossible to go through withdrawal without professional assistance. Symptoms can include serious cravings, harsh flu-like symptoms, severe agitation, sleep problems and possible seizures. Death during opiate withdrawal has also been reported.
Opiate Replacement Therapy May Not Be The Answer For Everyone
People who try to withdrawal from opiates on their own may be fighting an uphill battle. Withdrawal can be overwhelming and the fear of this causes some to relapse over and over. Opiate replacement therapy with opiate agonists, or withdrawal management with partial opiate agonists may work for some people. These treatments tend to be more long term. Using opiates to treat opiate addiction is also risky because they can also lead to dependence.
Others may find that in-patient opiate treatment works better if detox is offered in a professional setting. This way, patients don't have to be on opiate replacement therapy long term. They may also find the support they need in a program that offers detox, counseling and other services.