TY - CHAP M1 - Book, Section TI - Opioid Analgesics & Antagonists A1 - Katzung, Bertram G. A1 - Kruidering-Hall, Marieke A1 - Trevor, Anthony J. PY - 2019 T2 - Katzung & Trevor's Pharmacology: Examination & Board Review, 12e AB - The opioids include natural opiates and semisynthetic alkaloids derived from the opium poppy, pharmacologically similar synthetic surrogates, and endogenous peptides. On the basis of their interaction with several opioid receptors (μ[mu], δ [delta], and κ [kappa] receptors), individual drugs are classified as agonists, mixed agonist-antagonists, and antagonists at one or more of these receptors. Because of their psychic effects, opioids are important drugs of abuse and are responsible for severe personal and social problems.Opioid peptides (opiopeptins) released from nerve endings modulate transmission in the brain and spinal cord and in primary afferents via their interaction with one or more of the above receptors. Most of the pharmacologic actions of opiates and synthetic opioid drugs are effected via their interactions with opioid peptide receptors. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessmedicine.mhmedical.com/content.aspx?aid=1179220990 ER -