TY - CHAP M1 - Book, Section TI - Opioid Analgesics & Antagonists A1 - Katzung, Bertram G. A1 - Kruidering-Hall, Marieke A1 - Tuan, Rupa Lalchandani A1 - Vanderah, Todd W. A1 - Trevor, Anthony J. PY - 2021 T2 - Katzung & Trevor's Pharmacology: Examination & Board Review, 13e 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 euphoric effects, μ-opioid agonists are important drugs of abuse and are responsible for severe personal and social problems.Opioid peptides released from nerve endings modulate neurotransmission in the brain, spinal cord, and in primary afferents via their interaction with one or more of the above opioid receptors. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1180556894 ER -