NaloxoneBuprenorphineNarcotic AntagonistsOpioid-Related DisordersMorphineReceptors, OpioidEndorphinsEnkephalin, MethionineReceptors, Opioid, muNarcoticsAnalgesics, OpioidOpioid PeptidesMorphine DependenceEnkephalinsbeta-EndorphinEnkephalin, LeucineDrug OverdoseReceptors, Opioid, kappaSubstance Withdrawal SyndromeAnalgesicsNaltrexoneEnkephalin, Ala(2)-MePhe(4)-Gly(5)-Receptors, Opioid, deltaMorphinansDrug TolerancePentazocineEnkephalin, Leucine-2-AlanineLoperamideNalorphineLevallorphanLevorphanolCyclazocine