R. Cotton, R. James
1985
Citations
0
Influential Citations
3
Citations
Journal
Annual Reports in Medicinal Chemistry
Abstract
Publisher Summary This chapter discusses the therapeutic use of analgesics, opioid drugs, and their receptors. In this chapter, reviews of the use of opioid analgesics in cancer treatment and anesthesia have been provided. Long-lasting pain relief, free from serious side effects, has been described by epidural administration in a variety of chronic conditions. The potential use of opioid antagonists in the treatment of disorders, such as shock and stroke, that may involve endogenous opioids, has been discussed in the chapter. Newer analgesics include MR-1268, shown to be as effective as pentazocine in severe postoperative pain. Zenazocine and bromadoline are both reported to be in phase II clinical trials. The existence of three types of opioid receptor μ, δ, and K is now firmly established. The effect of Na + and GTP, or its non-hydrolyzable analogue GppNHp on opioid receptor binding has been the focus of much recent attention. The affinities of opioid agonists and, to a lesser extent, partial agonists for the β-receptor are markedly reduced in the presence of these agents. The hamster vas deferens is reported to contain opiate receptors exclusively of the δ-type. The inhibitory effect of δ-agonists on electrically stimulated contractions of this tissue could be attenuated by naloxone and equally effectively by a new δ-receptor antagonist. Several studies, using a range of μ- or δ-selective peptides, show that analgesic potencies correlate well with affinities for the μ-receptor but not for the δ-receptor. Considerable progress has been reported in the isolation and characterization of opioid receptors. The problem of characterizing that opioids are responsible for modulating various forms of endogenous analgesia and where in the body they act is complex.