Methadone is a narcotic analgesic prescribed for the management of moderate to severe pain and for the treatment of opiate dependence (Heroin, Vicodin, Percocet, Morphine). It is administered either orally, or by intravenous or intra-muscular injection. The duration of effect of methadone is 12 – 24 hours. Its major urinary excretion products are methadone, EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylprryolidine), and EMDP (2- ethyl-5-methy -3, 3-diphenylpyrrolidine). These Identify Diagnostics drug tests yield a positive result when the concentration of Methadone in urine exceeds 300 ng/mL. See also our EDDP panel which detects methadone that has been metabolized by the body rather than methadone that may have been manually added to the urine sample.