antiopiate

1. not comparableCounteracting an opiate.

   That is, the location of heroin use can serve as a conditioned stimulus for the antiopiate response. When the user injects the drug in a different location, the well-developed antiopiate response does not occur […]

   2000, Lester A. Lefton, Psychology

plural antiopiates

1. A drug that has an antiopiate effect.

   Cholestyramine, however, may exert effects different from decreasing the enterohepatic circulation of bile acids including the release of endogenous antiopiates (e.g., cholecystokinin) that may result in a decrease in the perception of pruritus.

   2012, C. J. Hawkey, Jaime Bosch, Joel E. Richter, Textbook of Clinical Gastroenterology and Hepatology, page 78