1. Copyright (c) 2004 Elsevier Inc. All rights reserved. Opioid (Narcotic) Analgesics, Opioid Antagonists, and Nonopioid Centrally Acting Analgesics Chapter 27

2. Copyright (c) 2004 Elsevier Inc. All rights reserved. Opioid (Narcotic) Analgesics Analgesic –Relieves pain without loss of consciousness Opioid – Drug similar to morphine – Derived from opium Narcotic

3. Copyright (c) 2004 Elsevier Inc. All rights reserved. Morphine Prototype of strong opioid analgesics Used for relief of moderate and severe pain Decreases sensation of pain Decreases the emotional reaction to pain

4. Copyright (c) 2004 Elsevier Inc. All rights reserved. Adverse effects –Respiratory depression –Constipation –Orthostatic hypotension –Urinary retention – Biliary colic –Cough suppression –Emesis –Increased IOP –Miosis – Euphoria/dysphoria – Sedation – Miosis Morphine

5. Copyright (c) 2004 Elsevier Inc. All rights reserved. Tolerance –Increasing doses to obtain same response –Develops with analgesia, euphoria, sedation, respiratory depression –Cross-tolerance to other opioid agonists

6. Copyright (c) 2004 Elsevier Inc. All rights reserved. Physical Dependence Abstinence syndrome occurs if drug abruptly stopped Abstinence syndrome is dependent on –Half-life of drug –Degree of physical dependence

7. Copyright (c) 2004 Elsevier Inc. All rights reserved. Opioid Overdose Classic triad –Coma –Respiratory depression –Pinpoint pupils Treatment –Ventilatory support –Opioid antagonist Naloxone (Narcan)