1. ANALGESIC DRUGS – LILLEY – CH 11 CNS DEPRESSANTS & MUSCLE RELAXANTS – LILLEY– CH 13 CNS STIMULANTS -LILLEY – CH 14 ANTIEPLEPTIC DRUGS – LILLEY – CH 15 ANTIPARKINSONIAN DRUGS – LILLEY -- CH 16 Central Nervous System

2. CNS Pharmacology Objectives Discuss the the actions and uses of an opioid agonist, agonist- antagonist, and antagonist Describe how the nursing process is applied to clients receiving sedative-hypnotic agents Describe the role of the nurse in promoting client compliance with drug therapy for seizure activity Identify the variety of conditions and disorders being treated with CNS stimulants Describe the actions and intended effects of the classes of medications used in the treatment of Parkinson’s disease

3. CNS- Analgesic Agents Pain Defn:  Medications that relieve pain without causing loss of consciousness  Painkillers

4. CNS – Analgesic Agents Pain Pain  Whatever the patient says it is – Perception  It exists whenever the patient says it exists  It’s an unpleasant sensory and emotional experience associated with actual or potential tissue damage  Pain is a personal and individual experience

5. CNS– Analgesic Agents Pain Subjective:  Pain Threshold:  The level of stimulus needed to produce the perception of pain  A measure of the physiologic response of the nervous system  Pain Tolerance:  The amount of pain a patient can endure without its with normal function with normal function  The point at which the pain becomes unbearable

6. CNS – Analgesic Agents Classification of Pain Classification of pain by onset and duration:  Acute pain:  Sudden onset  Usually subsides once treated  Chronic pain:  Persistent or recurring  Often difficult to treat

7. CNS – Analgesic Agents Classification of Pain Classification of Pain  Somatic  Visceral  Vascular  Referred  Neuropathic  Phantom  Cancer  Psychogenic  Central

8. CNS – Analgesic Agents Pain Transmission Pain Transmission – Gate Theory  Impulses travel from damaged tissues and are sensed in the brain  Many current pain theories are aimed at altering this system  Substances released that stimulate nerve endings:  Bradykinin, histamine, potassium, prostaglandins, serotonin  Nerves stimulated:  “A” fibers: large fibers covered with myelin sheath, with rapid conduction – results: sharp & well localized pain  “C” fibers: small fibers with no myelin sheath, with slow conduction – results: dull and non-localized pain

9. CNS – Analgesic Agents Pain Transmission Pain fibers enter the spinal cord and travel up to the brain  Enter through the dorsal horn – “the gate”  The gate regulates the flow of sensory impulses to the brain  If no impulses are transmitted to higher centers in the brain, there is no pain perception  Activation of “A” fibers - closes the gate  Allows the brain to evaluate, identify and localize the pain & control the gate before it is open  Activation of “C” fibers – opens the gate

10. CNS – Analgesic Agents Pain Transmission Body has endogenous neurotransmitters  Enkephalins  Endorphins Produced by body to fight pain Bind opioid receptors & inhibit transmission by “closing the gate” Examples:  Runner’s high  Rubbing a painful area stimulates large sensory fibers – result: gait closed, pain recognition reduced Opiates use the same pathway

11. CNS – Analgesic Agents Agonist Binds to an opioid pain receptor in the brain and causes an analgesic response

12. CNS – Analgesic Agents Opioids - Agonists Chemical CategoryOpioid Drugs meperidine-like drugsAgonist: merperidine (Demerol, Pethidine), fentanyl (Sublimaze, Durgesic) Methadone-like drugsAgonist: C-II Dolphine, propoxyphene Morphine-like drugsAgonist: C-II: Morphine, Duramorph, Roxanol, MS- Contin, hydromorphone (Dilaudid), oxymorphine, levorphanol, codeine, hydrocodone, oxycodone (OxyContin); C-I: heroin Opioid/Acetaminophen or ASA Combinations Agonist: C-II: oxycodone with Tylenol (Percocet); oxycodone with ASA (Percodan); hydrocodone with Tylenol (Vicodin, Lorcet)

13. CNS – Analgesic Agents Opioid Analgesics Opioid pain relievers: Narcotics that contain “opium”, derived from the opium poppy  Very powerful  Addictive Indications: PAIN Management  alleviate severe to moderate pain  Often given with adjuvant analgesic agents to assist pain relief: NSAIDS, Antidepressants, Anticonvulsants, corticosteroids  Cough center suppression  Treatment of diarrhea  Balanced anesthesia

14. CNS –Analgesic Agents Antagonists Reverse the effects of these agents on pain receptors Bind to a pain receptor and exert no response Also known as competitive antagonists Medications:  naloxone (Narcan) – treat overdose  Naltrexone (Trexan) – maintenance of opioid-free state & psychosocial tx of alcoholism

15. CNS – Analgesic Agents Side Effects Euphoria CNS depression Nausea and vomiting Respiratory depression Urinary retention Diaphoresis and flushing Pupil constriction (miosis) Constipation Itching

16. CNS – Analgesic Agents Opioid Overdose Triad  Respiratory depression  Respiratory rate <12/min, dyspnea, diminished breath sounds, or shallow breathing  Decreased level of consciousness  Pinpoint Pupils (miosis)

17. CNS – Analgesic Agents Opioid Effects Tolerance  Common physiologic effect of chronic opioid tx  Larger doses are required to produce the same level of analgesia Physical Dependence  Physiologic adaptation of the body to the presence of an opioid Tolerance and physical dependence are expected with long term opioid treatment, and should not be confused with: Psychological Dependence  Pattern of compulsive drug use characterized by continued craving for an opioid and the need to use the opioid for effects other than pain relief

18. CNS – Analgesic Agents Withdrawal / Abstinence Syndrome  Occurs when abruptly discontinued or when an opioid antagonist is administered  anxiety, irritability, chills & hot flashes, joint pain, lacrimation, rhinorrhea, diaphoresis, nausea, vomiting, abdominal cramps, diarrhea

19. CNS – Analgesic Agents Non-opioids acetaminophen (Tylenol): blocks peripheral pain impulses by inhibition of prostaglandin synthesis & lowers febrile body temp – hypothalamus  Max dose for healthy adult 4,000 mg per day  Check combinations of drug products acetylsalicylic acid (Aspirin): anti- inflammatory, anti-pyretic, analgesic, anti-rheumatic properties  Check when ordered with NSAIDs or Plavix

20. CNS -- Analgesic Agents Non-steroidal anti-inflammatory drugs NSAIDs – reduce inflammation  Block Leukotriene (lipoxygenase) pathway  Salicylates  Cox1 isoform of the enzyme promotes synthesis of homeostatic prostaglandins  Indomethacin (Indocin); ibupofen (Motrin); naproxen (Naprosyn); nabumetone (Relafen)  Cox2 inhibitors block the cyclooxygenase cox2 pathway - prevent GI side effects  Celecoxib (Celebrex)

21. CNS – Analgesic Agents Medication Orders Joint Commission Requirements  Pain medication for severe, moderate, and/or mild pain Example: Morphine 5 mg IM q4h prn severe pain Percocet 1-11 tablets q6h prn moderate pain Tylenol 650 mg po q4h prn mild pain

22. CNS – Analgesic Agents Interactions Dangerous interactions may occur if taken with alcohol Should not be taken in the presence of:  Liver dysfunction  Possible liver failure  When taking other hepatotoxic drugs

23. CNS – Analgesic Agents Nursing Implications Assessment  Allergy History / Idiosyncratic Reactions  History of alcohol use  Medical history – possible contraindications  Medication reconciliation – possible drug interactions  Thorough pain assessment – Fifth Vital Sign  Intensity, character, onset, location, description, precipitating and relieving factors, type, remedies, and other pain treatments  Pain Scale / Nonverbal  Baseline vital signs and pulse oximetry  Monitor for side effects, change in pt status, & status of pain relief

24. CNS – Analgesic Agents Nursing Implications Patient Education  Do not take other medications or OTC medications unless prescribed by physician  Pain scale  Signs & Symptoms of drug allergies or adverse effects  Safety measures  Pain management – includes both pharmacologic and non-pharmacologic approaches:  Position of comfort, distraction, therapeutic touch, comfort foods & beverages, visitors, spirituality, presence!

25. CNS – Analgesic Agents Nursing Implications Nursing Actions:  Administer oral forms with food to minimize gastric upset  Ensure safety measures – prevent orthostatic hypotension  Withhold dose and contact physician with any change in pt status  Check dosages carefully  Follow proper administration guidelines – po, sq, IM, IV – including dilution, rate of administration  Side Effects: constipation – increase fluids, stool softeners

26. CNS – Analgesic Agents Nursing Implications Monitor for therapeutic effects  Decreased complaint of pain  Decreased severity of pain  Increased periods of comfort  Improved activities of daily living, appetite, and sense of well- being  Decreased fever (acetaminophen & NSAIDs)

27. CNS – Analgesic Agents For the best results in treating severe pain associated with pathologic spinal fractures related to metastatic bone cancer, which type of dosage schedule should be used? Plan medication administered: a. As needed. b. Around the clock. c. On schedule during waking hours only. d. Around the clock, with added doses as needed for breakthrough pain.

28. CNS Analgesic Agents A patient is receiving an opioid via a PCA pump as part of the postoperative pain management program. During rounds, the nurse notices that his respirations are 8 breaths per minute and he is extremely lethargic. After stopping the opioid infusion, what should the nurse do next? a. notify the charge nurse b. administer oxygen c. administer an opiate antagonist per standing orders d. perform a thorough assessment, including mental status examination