Mouse anti-Methadone monoclonal antibody for ELISA. Methadone is a rigorously well-tested medication that is safe and efficacious for the treatment of narcotic withdrawal and dependence. For more than 30 years this synthetic narcotic has been used to treat opioid addiction. Heroin releases an excess of dopamine in the body and causes users to need an opiate continuously occupying the opioid receptor in the brain. Methadone occupies this receptor and is the stabilizing factor that permits addicts on methadone to change their behavior and to discontinue heroin use.