Preface [Hot Topic: New Vistas in the Treatment of Pain (Executive Editor: Dr. Joannes T.M. Linders) Pages from 701-759]

In this issue of Current Pharmaceutical Design, five manuscripts delve deep into the history and present day studies of morphine and related opioids, which have been the cornerstone of pain treatment since ancient history. Sabatowski [1] presents a history of pain treatment, starting from the early day opium use in Sumeria and Egypt, mandrake in the middle ages, and passing via Serturner, who in 1805 described for the first time morphine in its pure form as the active, analgesic principle of opium, finally arriving to the pain theories from the 19 th and 20 th century. The first total synthesis of morphine, the finding of the opioid antagonists, the discovery of the synthetic analgesics Fentanyl* , and its analogs by Paul Janssen during the 1950s, the discovery of the enkephalins and endorphins, the body's endogenous analgesics, and the characterization of three opioid receptors during the seventies were other milestones in the history of pain treatment. In the sixties and seventies, Bentley studied the orvinols, a class of rigid morphinans with extraordinary potency.They resulted from the Diels-Alder adducts of thebaine with ethyl acrylate or methyl vinyl ketone. Because of their rigidity, they formed the basis of a description of the features of the opioid receptor, which, as we know now, was in fact the μ-opioid receptor. Lewis and Husbands [2] took up the study of the compounds again, and using modern chemistry and pharmacology, arrived at a new model for the κ-opioid receptor. Nonpeptide ligands for the third opioid receptor, the d receptor, are discussed by Calderon and Coop [3]. The discovery of SNC-80, the first of a new class of selective, nonpeptide d-agonists, initiated a whole new direction in the study of opioids. Although the actions of morphine and its analogs have been mainly directed at the central nervous system, DeHaven-Hudkins and Dolle [4] make a case for a novel class of opioids, which are restricted to the peripheral nervous system, therewith avoiding some of the centrally mediated side effects of the classical opioids. Finally, James Frost [5] gives a different view of opioid receptor in a literal sense. He describes the application of positron emission tomography (PET) in the visualization of opioid receptors, and its application in the study of pain phenomena. Lastly, I would like to express my sincere thanks to all collaborators to this issue of Current Pharmaceutical Design for their efforts in describing some new vistas of pain treatment and their patience.