ATI RN Pharmacology for Nursing (8th Edition) Chapter 15 PDF

CHAPTER 15 UNIT 2 MEDICATIONS AFFECTING THE NERVOUS SYSTEM Succinylcholine CHAPTER 15 Miscellaneous Mimics ACh by binding with cholinergic receptors at the Central Nervous...

CHAPTER 15 UNIT 2 MEDICATIONS AFFECTING THE NERVOUS SYSTEM Succinylcholine CHAPTER 15 Miscellaneous Mimics ACh by binding with cholinergic receptors at the Central Nervous neuromuscular junction. This agent fills the cholinergic receptors, preventing ACh from binding with them, and System Medications causes sustained depolarization of the muscle, resulting in muscle paralysis. Short duration of action because of degradation by the plasma enzyme pseudocholinesterase. Neuromuscular blocking agents have various Pancuronium, atracurium, vecuronium uses, including causing muscle relaxation Block ACh from binding with cholinergic receptors during general anesthesia, control of seizures at the motor end plate. Muscle paralysis occurs during electroconvulsive therapy, and because of inhibited nerve depolarization and skeletal muscle contraction. suppression of gag reflex during endotracheal Reversal agent: neostigmine intubation. Medications include succinylcholine and vecuronium. THERAPEUTIC USES Neuromuscular blocking agents are used as adjuncts to Muscle relaxants and antispasmodic agents can general anesthesia to promote muscle relaxation. These agents are used to control spontaneous respiratory affect both the central and peripheral nervous movements in clients receiving mechanical ventilation. systems. These agents are used for spasticity These agents are used as seizure control during electroconvulsive therapy. related to muscle injury, cerebral palsy, spinal Neuromuscular blocking agents are used during cord injury, and multiple sclerosis. Agents endotracheal intubation and endoscopy. include diazepam, baclofen, and dantrolene. Bethanechol, a muscarinic agonist, is used for COMPLICATIONS urinary retention. Oxybutynin, a muscarinic Respiratory arrest antagonist, is used for neurogenic bladder. From paralyzed respiratory muscles NURSING ACTIONS Neuromuscular Maintain continuous cardiac and respiratory monitoring. Have equipment ready for resuscitation and mechanical blocking agents ventilation. Monitor for return of respiratory function when SELECT PROTOTYPE MEDICATION medication is discontinued. Depolarizing neuromuscular blockers: Succinylcholine Administer a cholinesterase inhibitor, neostigmine, to Nondepolarizing neuromuscular blockers: Pancuronium reverse the action of nondepolarizing neuromuscular blocking agents as needed. OTHER MEDICATIONS: Nondepolarizing neuromuscular blockers Atracurium ATRACURIUM Cisatracurium Rocuronium Hypotension Vecuronium Due to histamine release NURSING ACTIONS: Monitor for decreased blood pressure. PURPOSE Administer antihistamine if indicated. EXPECTED PHARMACOLOGICAL ACTION SUCCINYLCHOLINE Nondepolarizing neuromuscular blocking agents block Prolonged apnea acetylcholine (ACh) at the neuromuscular junction, resulting in muscle relaxation and hypotension. They do Low pseudocholinesterase activity can lead to not cross the blood-brain barrier, so complete paralysis prolonged apnea. is achieved without loss of consciousness or decreased NURSING ACTIONS pain sensation. Test blood or administer a small test dose for clients suspected of having low levels of pseudocholinesterase. Withhold medication if pseudocholinesterase activity is low. RN PHARMACOLOGY FOR NURSING CHAPTER 15 MISCELLANEOUS CENTRAL NERVOUS SYSTEM MEDICATIONS 117  Malignant hyperthermia NURSING ADMINISTRATION Manifestations include muscle rigidity accompanied by Clients must receive continuous cardiac and respiratory increased temperature, as high as 43° C (109.4° F). monitoring during therapy. Monitor clients following administration of a NURSING ACTIONS neuromuscular blocker for respiratory depression. Have Monitor vital signs. life support equipment available. Stop succinylcholine and other anesthetics. Continue to carefully monitor for return of Administer oxygen at 100%. respiratory function. Initiate cooling measures including administration of Have a cholinesterase inhibitor available to reverse iced 0.9% sodium chloride, applying a cooling blanket, nondepolarizing neuromuscular blocking agents. and placing ice bags in groin and other areas. Administer dantrolene to decrease metabolic activity of skeletal muscle. NURSING EVALUATION OF Muscle pain MEDICATION EFFECTIVENESS Depending on therapeutic intent, effectiveness can be After 12 to 24 hr postoperative, clients can experience evidenced by the following. muscle pain in the upper body and back. Muscle relaxation during surgery NURSING ACTIONS: Notify the provider to consider No spontaneous respiratory movements in clients short-term use of muscle relaxant. receiving mechanical ventilation Absence of seizures in clients receiving CLIENT EDUCATION: This response is not unusual and electroconvulsive therapy eventually will subside. Successful endotracheal intubation Hyperkalemia NURSING ACTIONS Muscle relaxants and antispasmodics Monitor potassium levels. Observe for manifestations of hyperkalemia. Do not use succinylcholine for clients who have severe SELECT PROTOTYPE MEDICATION burns, multiple trauma, or upper motor neuron injury. Centrally acting muscle relaxants: Diazepam Peripherally acting muscle relaxants: Dantrolene CONTRAINDICATIONS/PRECAUTIONS OTHER MEDICATIONS: Centrally acting muscle relaxants Baclofen Pregnancy Risk Category C Cyclobenzaprine Succinylcholine is contraindicated in clients who have Tizanidine risk of hyperkalemia (major trauma, severe burns). Use cautiously in clients who have myasthenia gravis, respiratory dysfunction, or fluid and electrolyte imbalances. PURPOSE Note that neuromuscular blocker medications Diazepam are not anesthetics and therefore have no effect EXPECTED PHARMACOLOGICAL ACTION: Acts in the on hearing, thinking, or ability to feel pain. CNS by mimicking the actions of GABA at receptors in the spinal cord and brain to produce sedative effects and depress spasticity of muscles. INTERACTIONS THERAPEUTIC USES Concurrent use with general anesthetics (common during Muscle spasm related to muscle injury and spasticity surgery) can cause extreme neuromuscular blockade. Anxiety and panic disorders NURSING ACTIONS: Reduce dosage of neuromuscular Insomnia blocker to prevent this effect. Status epilepticus Aminoglycosides and tetracyclines can increase the Alcohol withdrawal effects of neuromuscular blockade. Anesthesia induction NURSING ACTIONS: Take complete medication history of clients who are to receive neuromuscular blockade. Cyclobenzaprine, tizanidine Monitor for prolonged neuromuscular blockage. EXPECTED PHARMACOLOGICAL ACTION: Act in the CNS Neostigmine and other cholinesterase inhibitors increase to enhance GABA and produce sedative effects and depress the effects of depolarizing neuromuscular blockers spasticity of muscles. They have no direct muscle relaxant (succinylcholine). action and so do not decrease muscle strength. NURSING ACTIONS: Monitor clients during neuromuscular THERAPEUTIC USES: Relief of muscle spasm related to blockade reversal after surgery. muscle injury 118 CHAPTER 15 MISCELLANEOUS CENTRAL NERVOUS SYSTEM MEDICATIONS CONTENT MASTERY SERIES  Baclofen Seizures EXPECTED PHARMACOLOGICAL ACTION: Acts in the CNS NURSING ACTIONS: Monitor for seizure activity. to enhance GABA, produce sedative effects, and depress CLIENT EDUCATION: Monitor for adverse effects and hyperactive spasticity of muscles. There are no direct notify the provider if they occur. effects on skeletal muscles. THERAPEUTIC USES: Relief of spasticity related to cerebral palsy, spinal cord injury, and multiple sclerosis DANTROLENE Hepatic toxicity Dantrolene Anorexia, nausea, vomiting, abdominal pain, jaundice EXPECTED PHARMACOLOGICAL ACTION: A peripherally acting muscle relaxant that acts directly on spastic NURSING ACTIONS muscles and inhibits muscle contraction by preventing Obtain baseline liver function studies and perform release of calcium in skeletal muscles. periodic follow-up liver function tests. Observe for indications of toxicity and notify the THERAPEUTIC USES provider if they occur. Relief of spasticity related to cerebral palsy, spinal cord Start at low doses and use only as long as is necessary. injury, and multiple sclerosis Treatment of malignant hyperthermia Muscle weakness NURSING ACTIONS: Monitor effectiveness of COMPLICATIONS the medication. CNS depression Sleepiness, lightheadedness, fatigue CONTRAINDICATIONS/PRECAUTIONS NURSING ACTIONS BACLOFEN AND DANTROLENE: Pregnancy Risk Start at low doses. Category C Can occur with all muscle relaxants and DIAZEPAM antispasmodic medications. Controlled Substance (Schedule IV) CLIENT EDUCATION Pregnancy Risk Category D Observe for potential adverse effects. Use these medications cautiously in clients Avoid hazardous activities (driving) and concurrent use who have impaired liver and renal function. of other CNS depressants, including alcohol. DIAZEPAM, CYCLOBENZAPRINE, TIZANIDINE INTERACTIONS CNS depressants (alcohol, opioids, antihistamines) have Hepatic toxicity with tizanidine additive CNS depressant effects. Anorexia, nausea, vomiting, abdominal pain, jaundice CLIENT EDUCATION: Avoid concurrent use. NURSING ACTIONS Obtain baseline liver function and perform periodic NURSING ADMINISTRATION follow-up liver function tests. Observe for indications of toxicity and notify the Provide assistance as needed in self-administration of provider if they occur. medication and performance of ADLs. Start at a low dose and use only as long as is necessary. CLIENT EDUCATION Take medications as prescribed. Physical dependence from chronic long-term use Do not stop taking the medication abruptly to avoid CLIENT EDUCATION: Do not discontinue the withdrawal reaction. medication abruptly. Avoid CNS depressants while using these medications. BACLOFEN NURSING EVALUATION OF Nausea, constipation, urinary retention MEDICATION EFFECTIVENESS Depending on therapeutic intent, effectiveness can be NURSING ACTIONS: Monitor I&O. evidenced by the following. CLIENT EDUCATION Absence of muscle rigidity and spasms, good Monitor for adverse effects and notify the provider if range of motion they occur. Absence of pain Take with meals to reduce gastric upset. Increased ability to perform ADLs Increase intake of high-fiber foods. RN PHARMACOLOGY FOR NURSING CHAPTER 15 MISCELLANEOUS CENTRAL NERVOUS SYSTEM MEDICATIONS 119  Muscarinic agonists Muscarinic antagonists SELECT PROTOTYPE MEDICATION: Bethanechol SELECT PROTOTYPE MEDICATION: M3 receptor selective: oxybutynin OTHER MEDICATIONS Cevimeline OTHER MEDICATIONS Pilocarpine M3 receptor selective: Darifenacin, solifenacin Acetylcholine Nonselective: Tolterodine, fesoterodine, trospium PURPOSE PURPOSE EXPECTED PHARMACOLOGICAL ACTION: Stimulation EXPECTED PHARMACOLOGICAL ACTION: Inhibit muscarinic of muscarine receptors of the GU tract, thereby causing receptors of the detrusor muscle of the bladder, which relaxation of the trigone and sphincter muscles and prevents contractions of the bladder and the urge to void contraction of the detrusor muscle to increase bladder THERAPEUTIC USES pressure and excretion of urine Overactive bladder THERAPEUTIC USES Pre-anesthetic medication Nonobstructive urinary retention, usually Disorders and procedures of the eye postoperatively or postpartum Bradycardia On an investigational basis to treat Intestinal hypertonicity and hypermotility gastroesophageal reflux COMPLICATIONS COMPLICATIONS Anticholinergic effects Extreme muscarinic stimulation can result in increased gastric acid secretion, abdominal cramps, diarrhea, Constipation, dry mouth, blurred vision, photophobia, dry sweating, tearing, urinary urgency, bradycardia and eyes, tachycardia, anhydrosis hypotension; bronchoconstriction CLIENT EDUCATION: Increase dietary fiber, consume 2 to NURSING ACTIONS: Administer on an empty stomach to 3 L/day fluid from beverage and food sources, sip fluids, reduce effects. and avoid driving or other hazardous activities if vision is impaired. CLIENT EDUCATION: Report adverse effects if they occur. Monitor for bradycardia and hypotension. CNS, cardiovascular effects CNS effects: hallucinations, confusion, insomnia, CONTRAINDICATIONS/PRECAUTIONS nervousness Contraindicated in clients who have urinary or Cardiovascular effects: prolonged QT interval, tachycardia gastrointestinal obstruction, urinary bladder weakness, NURSING ACTIONS peptic ulcer disease, coronary insufficiency, asthma and Avoid use in older adult clients. hyperthyroidism. Monitor ECG. CLIENT EDUCATION: Report manifestations to the NURSING ADMINISTRATION provider. Discontinue medication. Administer by oral route, 1 hr before or 2 hr after meals to minimize nausea and vomiting. Monitor I&O. CONTRAINDICATIONS/PRECAUTIONS Contraindicated in clients who have glaucoma, myasthenia gravis, paralytic ileus, GI or GU obstruction, or NURSING EVALUATION OF urinary retention. MEDICATION EFFECTIVENESS Use cautiously in children and older adults. Use cautiously in clients who have gastroesophageal reflux Depending on therapeutic intent, effectiveness can be disease, heart failure, or kidney or liver impairment. evidenced by relief of urinary retention. 120 CHAPTER 15 MISCELLANEOUS CENTRAL NERVOUS SYSTEM MEDICATIONS CONTENT MASTERY SERIES  INTERACTIONS Application Exercises Antihistamines, tricyclic antidepressants, or phenothiazines used concurrently can result in extreme 1. A nurse in the operating room is caring for a client muscarinic blockage. who received a dose of succinylcholine. During the operation, the client suddenly develops rigidity and a NURSING ACTIONS: Concurrent use is not recommended. rise in body temperature. The nurse should expect a prescription for which of the following medications? A. Neostigmine NURSING ADMINISTRATION B. Naloxone Oral formulations are available as syrup, C. Dantrolene immediate-release (IR) tablets, and also extended-release D. Vecuronium (ER) tablets, which minimize anticholinergic effects. CLIENT EDUCATION Swallow ER tablets whole and avoid chewing or 2. A nurse in the post-anesthesia care unit is caring for a client who is experiencing malignant crushing the tablets. The shell of ER tablets will be hyperthermia. Which of the following actions eliminated whole in the stool. should the nurse take? (Select all that apply.) The transdermal patch is administered two times per A. Place a cooling blanket on the client. week. Apply to dry skin of the hip, abdomen, or buttock B. Administer oxygen at 100%. and to rotate sites. C. Administer iced 0.9% sodium chloride. D. Administer potassium chloride IV. NURSING EVALUATION OF E. Monitor core body temperature. MEDICATION EFFECTIVENESS Depending on therapeutic intent, effectiveness can be 3. A nurse is teaching a client who has a new prescription evidenced by a decrease in urinary urgency and frequency, for baclofen to treat muscle spasms. Which of the nocturia, and urge incontinence. following statements by the client indicates an understanding of the teaching? (Select all that apply.) A. “I will stop taking this medication right away if I develop dizziness.” B. “I know the doctor will gradually increase Active Learning Scenario my dose of this medication for a while.” C. “I should increase fiber to prevent A nurse manager in a surgical center is reviewing constipation from this medication.” nursing responsibilities regarding administration D. “I won’t be able to drink alcohol while of succinylcholine. Use the ATI Active Learning I’m taking this medication.” Template: Medication to complete this item. E. “I should take this medication on an empty stomach each morning.” THERAPEUTIC USES: Identify two common indications for use. MEDICATION ADMINISTRATION: Identify two nursing 4. A nurse is reviewing the medical record of a client responsibilities regarding the use of succinylcholine. who reports urinary incontinence and asks about a prescription for oxybutynin. The nurse should recognize that oxybutynin is contraindicated in the presence of which of the following conditions? A. Bursitis B. Sinusitis C. Depression D. Glaucoma 5. A nurse is assessing a client who has a prescription for bethanechol to treat urinary retention. The nurse should identify that which of the following findings is a manifestation of muscarinic stimulation? A. Dry mouth B. Hypertension C. Excessive perspiration D. Fecal impaction RN PHARMACOLOGY FOR NURSING CHAPTER 15 MISCELLANEOUS CENTRAL NERVOUS SYSTEM MEDICATIONS 121  Application Exercises Key Active Learning Scenario Key 1. A. Neostigmine is a cholinesterase inhibitor used to Using the Active Learning Template: Medication reverse the effects of nondepolarizing neuromuscular THERAPEUTIC USES blockers. It can delay inactivation of succinylcholine, a depolarizing neuromuscular blocker. Endotracheal intubation B. Naloxone is used to reverse the effects of opioids. Electroconvulsive therapy It is not used to treat malignant hyperthermia. Endoscopy C. CORRECT: Muscle rigidity and a sudden rise in Adjunct to mechanical ventilation temperature is a manifestation of malignant hyperthermia. Muscle relaxation during surgery Dantrolene acts on skeletal muscles to reduce metabolic activity and treat malignant hyperthermia. MEDICATION ADMINISTRATION D. Vecuronium is an intermediate-acting Clients must receive continuous cardiac and nondepolarizing neuromuscular blocker. It is not respiratory monitoring during therapy. useful in treating malignant hyperthermia. Monitor clients following administration of a neuromuscular blocker for respiratory depression and have life support equipment available. NCLEX® Connection: Pharmacological and Parenteral Therapies, Expected Actions/Outcomes Continue to carefully monitor for return of respiratory function. Succinylcholine is contraindicated for clients at risk for hyperkalemia (trauma, severe burns). 2. A. CORRECT: Apply a cooling blanket and NCLEX® Connection: Pharmacological and Parenteral Therapies, apply ice to the axilla and groin. Adverse Effects/Contraindications/Side Effects/Interactions B. CORRECT: Administer oxygen at 100% to treat decreased oxygen saturation. C. CORRECT: Take action to decrease the client’s body temperature by administering iced IV fluids. D. A client who has malignant hyperthermia is at risk for hyperkalemia. E. CORRECT: Monitor core body temperature to prevent hypothermia and to determine progress with treatment measures. NCLEX® Connection: Pharmacological and Parenteral Therapies, Parenteral/Intravenous Therapies 3. A. Abrupt withdrawal from baclofen can result in a number of adverse effects, including visual hallucinations and seizures. B. CORRECT: The provider starts the client on a low dose, and the dose is increased gradually to prevent CNS depression. C. CORRECT: The client should increase fluids and fiber to reduce the risk for constipation. D. CORRECT: The intake of alcohol and other CNS depressants can exacerbate the CNS depressant effects of baclofen. Therefore, the client is instructed to avoid CNS depressants while taking baclofen. E. The client should take baclofen with meals to reduce gastric upset. NCLEX® Connection: Pharmacological and Parenteral Therapies, Medication Administration 4. A. Oxybutynin is contraindicated in clients who have unstable cardiovascular disease, not bursitis. B. Oxybutynin is contraindicated in clients who have urinary retention, not sinusitis. C. Oxybutynin is contraindicated in clients who have myasthenia gravis, not depression. D. CORRECT: Oxybutynin is an anticholinergic and can increase intraocular pressure. It is contraindicated for clients who have glaucoma. NCLEX® Connection: Pharmacological and Parenteral Therapies, Adverse Effects/Contraindications/Side Effects/Interactions 5. A. Increased salivation is a manifestation of muscarinic stimulation. B. Hypotension is a manifestation of muscarinic stimulation. C. CORRECT: Bethanechol is a muscarinic agonist. Muscarinic stimulation can result in sweating. D. Diarrhea is an adverse effect of bethanechol. NCLEX® Connection: Pharmacological and Parenteral Therapies, Adverse Effects/Contraindications/Side Effects/Interactions 122 CHAPTER 15 MISCELLANEOUS CENTRAL NERVOUS SYSTEM MEDICATIONS CONTENT MASTERY SERIES