Home Resources Elephant Tranquilizer Might Be Exacerbating Heroin Epidemic Elephant Tranquilizer Might Be Exacerbating Heroin Epidemic September 15, 2016 Carfentanil is designed to knock out animals like elephants and moose, but drug dealers are lacing heroin with it. ResourcesVideosDrugsEpidemiologyEpigeneticsGeneticsHealth care and economicsHeroinPharmacologyPublic healthRecreational drugs