Drugs For the Control of Pain

Tri-Cyclic Antidepressant Atypical Antipsychotics OVERVIEW: Neuro System Drugs Tri-Cyclic Antidepressant escitalopram (Lexapro) Antidepressant / Anxiolytic MAOIs Benzodiazepines lorazepam (Ativan) diazepam (Valium) GABA Antagonist zolpidem (Ambien) A phenytoin (Dilantin) valproic acid (Depakote) Phenytoin-Like Drugs Succinimides ethosuximide (Zarontin) Barbiturates phenobarbital (Luminal) Phenothiazines chlorpromazine (Thorazine) Non-Phenothiazines halperidol (Haldol) Opioids morphine (Infumorph) Atypical Antipsychotics risperidone (Risperdal) Salicylates aspirin (ASA) NSAIDs ibuprofen (Motrin) Non-Opioid acetaminophen (Tylenol) Central Acting tramadol (Ultram) ergotamine (Cafergot) Sumatriptan (Imitrex) Anti-Migraine Opioid Antagonists naloxone (Narcan)

Pain Assessment Subjective experience for clients Numerical scales and surveys assist in assessment. Effective pharmacotherapy depends on Assessment of degree of pain Determining underlying disorders 3

Acute Pain Intense Defined period of time 4

Chronic Pain Over six months’ duration Interferes with daily activities 5

Nociceptive Pain Due to injury to tissues Sharp, localized Dull, throbbing, aching 6

Neuropathic Pain Due to injury to nerves Burning, shooting, numbing 7

Pain Transmission Nociceptor stimulation Spinal cord receives pain impulse through ∂ fibers – believed to signal sharp, well-defined pain C fibers – believed to conduct dull, poorly localized pain 8

Endogenous Opioids May modify sensory information, interrupting pain transmission Endorphins, dynorphins, ekaphalins 9

Interruption of Pain Transmission Several target areas Peripheral level CNS level Pharmacological Nonpharmacological 10

Nonpharmacologic Techniques for Pain Management Used alone or in conjunction with pharmacotherapy May allow for lower doses and possibly fewer drug-related adverse effects 11

Nonpharmacological Therapies Acupuncture Biofeedback Massage; therapeutic or physical touch Heat or cold Meditation or prayer Relaxation Art or music therapy Chiropractic manipulation Hypnosis TENS Energy therapies such a Reiki and Qi gong 12

Treatment for Intractable Cancer Pain Radiation or chemotherapy Relieving nerve stimulation Surgery Nerve block 13

Opioids A natural or synthetic morphine-like substance responsible for reducing moderate to severe pain 14

Opioid Receptors Receptors: mu, kappa, sigma, delta, epsilon For pain management mu and kappa receptors are most important Opioid agonist drugs: stimulate receptors Opioid antagonist drugs: block receptors 15

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Figure 18.2 Opioid receptors 17

Opioid Antagonists Block opioid activity Compete for opioid receptor Reverse symptoms of addiction, toxicity, and overdose Naxalone (Narcan) may be used to reverse respiratory depression and other acute symptoms Also used to diagnose overdose 18

Opioid Dependence Potential to cause physical and psychologic dependence Patient-controlled analgesia (PCA) Combinations with nonnarcotic analgesics 19

Treatment for Opioid Dependence Switch from IV and inhalation forms to methadone, the oral form Methadone maintenance Does not cure but avoids withdrawal symptoms Treatment may continue for many months and years 20

Newer Treatment Early treatment: buprenorphine (Subutex) Mixed opioid agonist-antagonist Sublingual route Later maintenance: Suboxone 21

Role of Nurse Careful monitoring of client’s condition Providing education Obtaining medical history Obtaining list of allergies Assessing client’s pain level Obtaining history of medications and alcohol and CNS-depressant use 22

Opioid Therapy Assess potential for opioid dependency Have narcotic antagonists available to reverse negative effects Assist with activity Monitor urine output for retention Monitor client’s bowel habits for constipation 23

Opioid Antagonist Therapy Continue careful monitoring of client’s condition Especially respiratory status Have resuscitative equipment available 24

Nonopioid Analgesics Careful monitoring of client’s condition and providing education is necessary Thorough assessment for hypersensitivity, bleeding disorders Through assessment for gastric ulcers, severe renal/hepatic disease, pregnancy 25

Nonopioid Analgesics (continued) Obtain laboratory tests on renal and liver function Pain assessment Monitor for side effects 26

Opioid (Narcotic) Analgesic Prototype drug: Opioid agonists (morphine) Mechanism of action: interacts with mu and kappa receptor sites Primary use: for analgesia and anesthesia Adverse effects: respiratory depression, sedation, nausea, and vomiting 27

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Table 18.2 (continued) Opiods for Pain Management 29

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Morphine Animation 31

Opioid Antagonists Prototype drug: naloxone (Narcan) Mechanism of action: interact with receptors Primary use: to reverse respiratory depression and other acute symptoms of opioid addiction, toxicity, overdose 32

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Opioids with Mixed Agonist-Antagonist Activity Example: Talwin Stimulate opioid receptor, thus causing analgesia Withdrawal symptoms and side effects not as intense as those of opioid agonists 34

Salicylates May increase action of oral hypoglycemic agents Prototype drug: aspirin (ASA) Mechanism of action: as anticoagulant, antipyretic, anti-inflammatory, and analgesic Adverse effects: with high doses may cause GI distress and bleeding May increase action of oral hypoglycemic agents 35

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Nonsteroidal Anti-inflammatory Drugs (NSAIDs) Prototype drug: ibuprofen (Motrin) Mechanism of action: to inhibit cyclooxygenase and prevent formation of prostaglandins Primary use: for mild or moderate pain and to reduce inflammation Adverse effects: GI upset, acute renal failure 37

Selective Cox-2 Inhibitors Prototype drug: celecoxib (Celebrex) Mechanism of action: is similar to the NSAIDs Primary use: to relieve pain, fever, inflammation Adverse effects: mild and related to GI system 38

Nonopioid Analgesics Prototype drug: acetaminophen (Tylenol) Mechanism of action: to treat fever: at the level of the hypothalamus and causes dilation of peripheral blood vessels enabling sweating and dissipation of heat Primary use: treatment of fever and to relieve pain Adverse effects: uncommon with therapeutic doses 39

Acetaminophen Animation Click here to view an animation on the topic of acetaminophen. 40

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Table 18.3 (continued) Nonopioid Analgesics 42

Centrally Acting Agents Prototype drug: tramadol (Ultram) Mechanism of action: has weak opioid activity Primary use: as centrally acting analgesic Adverse effects can include: CNS, GI, CV and dermatologic effects 43

Ergot Alkaloids Mechanism of action: to promote vasoconstriction Primary use: to terminate ongoing migraines Adverse effects: GI upset, weakness in the legs, myalgia, numbness and tingling in fingers and toes, angina-like pain, tachycardia 44

Triptans Prototype drug: sumatriptan (Imitrex) Mechanism of action: to act as serotonin agonists, constricting certain intracranial vessels Primary use: to abort migraines with or without auras Adverse effects: GI upset 45

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Table 18.4 (continued) Antimigraine Drugs 47

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Opioid Agonists Mechanism of action: to interact with specific receptors Primary use: to relieve moderate to severe pain; some used for anesthesia Examples: OxyContin, Percocet 49

Opiod Antangonists Blockers of opioid activity Used to reverse symptoms of opioid addiction, toxicity, overdose Examples: Revex, Narcan, Trexan 50

Nonopioid Analgesics Used for fever, inflammation, and analgesia Used for mild or moderate pain associated with inflammation Examples: Celebrex, Cataflam, Dolobid, Lodine, Nalfon 51

Antimigraine Agents Triptans Ergot alkaloids Serotonin agonists Act by constricting certain intracranial vessels Ergot alkaloids Act as vasoconstrictors Terminate ongoing migraines Migranal, Axert, Relpax, Frova 52

Review Questions

NCLEX-RN Review Question 1 The nurse teaches the patient relaxation techniques and guided imagery as an adjunct to medication for treatment of pain. The nurse explains that the major benefit of these techniques is that they: Are less costly Allow lower doses of drugs with fewer side effects Can be used at home Do not require self-injection 54

NCLEX-RN Review Question 1 – Answer Are less costly Allow lower doses of drugs with fewer side effects Can be used at home Do not require self-injection 55

NCLEX-RN Review Question 1 – Rationale Rationale: When used concurrently with medication, nonpharmacologic techniques may allow for lower doses and possibly fewer drug-related adverse effects. Relaxation techniques and imagery may also be used in the acute care setting. 56

NCLEX-RN Review Question 2 The nurse recognizes that opioid analgesics exert their action by interacting with a variety of opioid receptors. Drugs such as morphine act by: Activating kappa and blocking mu receptors Inhibiting mu and kappa receptors Activating mu and kappa receptors Blocking sigma and delta receptors 57

NCLEX-RN Review Question 2 – Answer Activating kappa and blocking mu receptors Inhibiting mu and kappa receptors Activating mu and kappa receptors Blocking sigma and delta receptors 58

NCLEX-RN Review Question 2 – Rationale Rationale: Some opioid agonists, such as morphine, activate both mu and kappa receptors. 59

NCLEX-RN Review Question 3 A patient admitted with hepatitis B is prescribed Vicodin 2 tablets for pain. The appropriate nursing action is to: Administer the drug as ordered Administer 1 tablet only Recheck the order with the health care provider Hold the drug until the health care provider arrives 60

NCLEX-RN Review Question 3 – Answer Administer the drug as ordered Administer 1 tablet only Recheck the order with the health care provider Hold the drug until the health care provider arrives 61

NCLEX-RN Review Question 3 – Rationale Rationale: Vicodin is a combination drug of hydrocodone and acetaminophen. Acetaminophen can be hepatotoxic, and this patient has hepatitis B, a chronic liver disorder. 62

NCLEX-RN Review Question 5 Nursing interventions for a patient receiving opioid analgesics over an extended period should include: Referring the patient to a drug treatment center Encouraging increased fluids and fiber in the diet Monitoring for GI bleeding Teaching the patient to self-assess blood pressure 63

NCLEX-RN Review Question 5 – Answer Referring the patient to a drug treatment center Encouraging increased fluids and fiber in the diet Monitoring for GI bleeding Teaching the patient to self-assess blood pressure 64

NCLEX-RN Review Question 5 – Rationale Rationale: Opioids suppress intestinal contractility, increase anal sphincter tone, and inhibit fluids into the intestines, which can lead to constipation. 65

NCLEX-RN Review Question 6 The most appropriate method to ensure adequate pain relief in the immediate postoperative period from an opioid drug would be to: Give the drug only when the family members report that the patient is complaining of pain. Give the drug every time the patient complains of acute pain. Give the drug as consistently as possible for the first 24 to 48 hours. Give the drug only when the nurse observes signs and symptoms of pain. 66

NCLEX-RN Review Question 6 – Answer Give the drug only when the family members report that the patient is complaining of pain. Give the drug every time the patient complains of acute pain. Give the drug as consistently as possible for the first 24 to 48 hours. Give the drug only when the nurse observes signs and symptoms of pain. 67

NCLEX-RN Review Question 6 – Rationale Rationale: Opioid pain relievers should be given as consistently as possible, and before the onset of acute pain, in the immediate postoperative period unless the patient’s condition does not allow the consistent dosing (e.g., vital signs do not support regular doses). Giving the drug only when the family members report that the patient is complaining of pain, every time the patient complains of acute pain, or only when the nurse observes signs and symptoms of pain. These methods of drug administration would potentially allow pain to become severe before being adequately treated. Patients or family members may not always report pain or may downplay the severity. Cultural norms may also influence the patient’s way of exhibiting pain. 68

Nursing Process

Drugs for Control of Pain Assessment Carefully monitor client’s condition Assess vital signs, especially respiratory status Assess client’s pain level: character, duration, location, intensity of pain Obtain history of medications, alcohol use 70

Drugs for Control of Pain (continued) Assessment Obtain medical history and history of migraine headaches Assess client’s stress levels and coping mechanisms Monitor for side effects and potential for dependency 71

Drugs for Control of Pain (continued) Nursing diagnosis Knowledge deficit—condition, therapeutic regimen, side effects Risk for dependency related to opioid therapy 72

Drugs for Control of Pain (continued) Planning Goal is to explain proper use of medication Client to be free of pain without dependency 73

Drugs for Control of Pain (continued) Implementation Encourage compliance with medication regimen Provide additional education 74

Drugs for Control of Pain (continued) Evaluation Client should have pain control with limited side effects, no dependency. Client verbalizes importance of taking prescribed medications. 75

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