n.
Organic compound, a potent synthetic narcotic drug, the most effective form of treatment for addiction to heroin and other narcotics (see drug addiction ).
It has been widely used in heroin-addiction programs in the U.S. since the 1960s. Though addictive itself, it is easier to stop using than heroin. It also causes no euphoric effects and does not lead to development of tolerance, so increasing doses are not required. A person taking a daily maintenance dose does not experience either heroin withdrawal symptoms or a heroin rush from any attempt to resume heroin, so heroin's psychological hold on the user can be broken.