Abstract: The present invention provides 2-, 3-, and 5- and/or 8-substituted, and/or side-chain substituted, dibenzoxazepine compounds of Formula I: ##STR1## wherein Y is sulfur, ##STR2## which are useful as analgesic agents for the treatment of pain, pharmaceutical compositions comprising a therapeutically-effective amount of a compound of Formula I in combination with a pharmaceutically-acceptable carrier, and a method for eliminating or ameliorating pain in an animal comprising administering a therapeutically-effective amount of a compound of Formula I to the animal.

Abstract: A fluorescence polarization immunoassay for detecting the presence of methadone in a test sample is provided, based upon competition between methadone and a fluorescently labeled tracer for the binding sites on an antibody specific for methadone. The concentration of methadone in the sample determines the amount of tracer that binds to the antibody. The amount of tracer-antibody complex formed can be quantitatively measured and is inversely proportional to the quantity of methadone in the sample. Tracers used as reagents and immunogens used to raise antibodies for use as reagents are also disclosed.