This document summarizes key aspects of opioid agonists and antagonists: 1. It classifies opioids as natural, semisynthetic, or synthetic, and describes the chemical structure of morphine. Morphine binds to mu, kappa, and sigma receptors in the central nervous system. 2. Endogenous opioid peptides like enkephalins and endorphins are derived from precursor proteins and act as neuromodulators or neurohormones. 3. Morphine is readily absorbed and distributed in the body, metabolized in the liver, and excreted by the kidneys. It provides analgesia and sedation by acting on the CNS but also causes respiratory depression, constipation

1. OPIOID AGONISTS AND ANTAGONISTS Prof. Dr. Shah Murad [email_address]