Chapter 10 Analgesics and Antipyretics

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Pain When nerve signals are sent to the brain (CNS) after feeling a hurtful sensation inside or outside the body, the brain perceives these signals as pain.  When the client complains of pain, it is important for the nurse to treat it.  Pain: the fifth vital sign

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Pain Transmission Tissue injury causes the release of:  Bradykinin  Histamine  Prostaglandins  Serotonin  These substances stimulate nerve endings, starting the pain process.

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Pain Transmission Gate Theory Most common and well-described theory of pain Uses the analogy of a gate to describe how impulses from injured tissues are sensed in the brain

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Pain Transmission in the Spinal Cord A fibers  Myelin sheath  Large fiber size  Conduct quickly  Sharp and well- localized C fibers  No myelin sheath  Small fiber size  Conduct slowly  Dull and nonlocalized

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Neurotransmitters Body has endogenous neurotransmitters  Endorphins  Enkephalins Produced by body to fight pain  Marathon runners and cyclists Bind to opioid receptors Inhibit transmission of pain by closing the gate

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Management of Pain Treat the cause. Select a safe analgesic. Select the analgesic that provides effective relief. Provide psychological support. Nursing actions: position change and back rub

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Analgesics Analgesic drugs relieve pain without causing loss of consciousness.

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opioid Analgesics Opium has been used for thousands of years to alleviate pain. Opium is derived from the poppy plant. Opium produces pain relief by attaching to pain receptors. Narcotics are derivatives of opium. Narcotics are strong pain relievers.

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Classifications of Opioid Analgesics Classifications based on their actions:  Agonist  Agonist-antagonist  Partial agonist

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Uses for Opioid Analgesics Main use: to alleviate moderate to severe pain Opioids are also used for:  Cough suppression  Diarrhea treatment

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Effects of Opioid Analgesics Euphoria Nausea and vomiting Respiratory depression Urinary retention Diaphoresis and flushing Pupil constriction (miosis) Constipation

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Complications of Opioid Analgesics Respiratory implications Constipation concerns

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opioid Analgesics: Nursing Assessments Perform a thorough history. Obtain baseline vital signs and assessments. Assess for potential contraindications and drug interactions.

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opioid Analgesics: Nursing Implications Oral forms–take with food Ensure safety measures

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opiates: Opioid Tolerance A common response to chronic opioid treatment Larger dose of opioids is required

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opiates: Physical Dependence Physiologic adaptation to the presence of an opioid If in need of pain relief, give the medication

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opiates: Psychological Dependence (Addiction) A pattern of compulsive drug use when the medication is not needed for physical pain relief

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opioid Analgesics: Nursing Implications Law: narcotics must be kept under a double lock (continues)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opioid Analgesics: Nursing Implications Pain management approaches Medical/nursing  Medicate clients before a procedure or an activity and/or  When they are complaining of pain Nursing  Back rub, musical therapy, and relaxation therapy (continued)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opioid Analgesics: Therapeutic Effects Monitor for therapeutic effects  Increased comfort  Activities of daily living improved

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opiate Antagonists Naloxone (Narcan) and naltrexone (ReVia)  Opiate antagonists  Bind to opiate receptors and prevent a response  Used for reversal of opioid-induced respiratory depression

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opioid Analgesics: Nursing Implications Rotate site for IM injections. Follow proper guidelines for IV administration, such as dilution and rate of administration. Check dosages carefully. (continues)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Opioid Analgesics: Nursing Implications Prevent constipation.  Provide fluid and fiber. Prevent respiratory depression. Provide instruction for clients.  Drug administration  Position changes (continued)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Analgesic Agents Analgesic agents  Salicylates (ASA)  Acetaminophen (Tylenol)  Combination narcotic and non-narcotic analgesics Anti-inflammatory analgesic agents  Nonsteroidal anti-inflammatory drugs (NSAIDs)

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved ASA (Acetylsalicylic Acid) Used for more than 100 years Action: peripherally interferes with synthesis of prostaglandins and chemical substances released from injured tissue Treats mild to moderate pain Antipyretic effect

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved ASA: Side Effects Gastrointestinal irritation and bleeding Increases bleeding time Tinnitus Children: Reye’s syndrome

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Analgesic Agents: Acetaminophen Mechanism of action  Blocks pain impulses peripherally  Relieves pain  Reduces a fever–antipyretic  Weak anti-inflammatory  Minimal effect on the central nervous system

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Acetaminophen: Side Effects Acute overdose causes hepatic necrosis.  Doses of 150 mg/kg  Long-term ingestion of large doses can result in nephropathy

Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Acetaminophen: Acute Overdose Treatment: acetylcysteine  Oral form  IV form now approved  Prevents the formation of hepatotoxic metabolites