Methadone Information
Drug Class: Narcotic Analgesic
Trade Names: Dolophine, Methadose
Description: Methadone is a synthetic opiate (opioid), first synthesized by German
scientists during World War II and made commercially available in the United States
in 1947. Although it was originally developed for use as an analgesic, methadone
is mainly used today as a substitute for heroin in order to relieve some of the
problems associated with heroin addiction. It is usually prescribed as a liquid
syrup to be taken orally, but is also manufactured as tablets and ampoules for
injection. Methadone maintenance programs are intended to reduce the risks associated
with heroin addiction, such as heroin overdose, HIV or hepatitis infection from
shared syringes, and risks due to criminal activity associated with the illicit
drug market. Methadone mimics many of the effects of opiates such as heroin. However,
there are many differences. For example, heroin produces an almost immediate "rush"
or brief period of euphoria, which wears off relatively quickly, resulting in
a strong craving to use more heroin. In contrast, methadone has a more gradual
onset of action when administered orally. Its effects can last up to 24 hours,
which allows the patient to take methadone only once a day without experiencing
withdrawal symptoms. Research has demonstrated that, when methadone is given in
regular doses by a physician, it has the ability to block the euphoria caused
by heroin if the individual does try to take heroin. Despite methadone's role
in the treatment of heroin addiction, it has addictive properties and also a high
potential for abuse on the street. Methadone enters the illicit drug market primarily
as a result of patients selling their prescriptions.
Excretion: In the
24-hour urine following a 5 mg oral methadone dose, unchanged methadone accounted
for 5% of the dose, EDDP for 5%, and EMDP for less than 1%. In the 24-hour urine
of methadone maintenance subjects, unchanged methadone may account for 5% to 50%
of the dose and EDDP for 3% to 25%, with large variations due to urine pH, urine
volume, dose, and rate of metabolism. Urinary concentrations of methadone and
EDDP in these subjects ranging from 1,000 ng/ml to 50,000 ng/ml are commonly encountered.