PHARMACOLOGY CONNECTIONS TO NURSING PRACTICE Second Edition CHAPTER 16 Review of Neurotransmitters and the Autonomic Nervous System Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Figure 16.1 Functional divisions of the nervous system. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Autonomic Nervous System • Three main activities – Contraction of smooth muscle of the bronchi, blood vessels, gastrointestinal tract, eye, and genitourinary tract – Contraction of cardiac muscle – Secretion of salivary, sweat, and gastric glands Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Structure and Function of the ANS • Two divisions – Sympathetic – Parasympathetic • Organs and glands – Receive nerves from both branches – Opposing actions Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Figure 16.2 Effects of the sympathetic and parasympathetic nervous systems. Source: From KROGH, DAVID, BIOLOGY: A GUIDE TO THE NATURAL WORLD, 5th Ed., © 2011. Reprinted and Electronically reproduced by permission of Pearson Education, Inc., Upper Saddle River, New Jersey. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Fight-or-Flight Response (SNS) • • • • • • • • Brain – Increased alertness and readiness Cardiovascular – Increased heart rate and blood pressure Musculoskeletal – Ready for sudden, intense physical activity GI – Liver produces more glucose for energy; Decreased peristalsis Respiratory – Dilation of bronchi, increased respirations Pupils – Dilation, increased vision Integumentary – Warm, increased perspiration Genitourinary – Decreased urine formation Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Rest-and-Digest (PNS) • GI – Increased secretions – Increased peristalsis • Cardiovascular – Decreased heart rate and blood pressure • Respiratory – Constriction of bronchi, decrease respirations Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Figure 16.3 Basic structure of an autonomic pathway. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban ANS Neurotransmitters • Norepinephrine (NE) • Acetylcholine (Ach) Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Figure 16.4 Receptors in the autonomic nervous system: (a) Sympathetic pathway: Ach is released at the ganglia (nicotinic receptor) and NE at the effector organ (adrenergic receptor). (b) Parasympathetic pathway: Ach is released at both the ganglia (nicotinic receptor) and effector organ (cholinergic receptor). Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Table 16.2 Types of Autonomic Receptors Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Figure 16.5 Life cycle of acetylcholine (Ach): (1) Ach is released into the synaptic cleft; (2) Ach binds to receptors on the postsynaptic membrane; (3) Ach is broken down into acetate and choline. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Figure 16.6 Life cycle of norepinephrine (NE): (1) NE is synthesized from the amino acid tyrosine; (2) NE is released into the synaptic cleft; (3) NE binds to receptors on the postsynaptic membrane; (4) NE is taken back into the presynaptic neuron; (5) NE is degraded by MAO; (6) Small amounts of NE are degraded by COMT. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Classification of Autonomic Drugs • Stimulation of SNS – Sympathomimetics, adrenergic-agonists • Stimulation of PNS – Parsympathomimetics, muscarinic agonists • Inhibition of SNS – Adrenergic antagonists or blockers • Inhibition of PNS – Anticholinergics, parasympatholytics, muscarinic blockers Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban PHARMACOLOGY CONNECTIONS TO NURSING PRACTICE Second Edition CHAPTER 17 Cholinergic Agonists Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Cholinergic Receptors 17.1 Drugs can activate cholinergic receptors either directly or indirectly. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Cholinergic Receptors • Can be activated directly or indirectly • Found in the autonomic nervous system at the ganglia and the neuroeffector junctions • Found in the somatic nervous system at the neuromuscular synapses Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Direct Cholinergic Agonists • Produce rest-and-digest responses – Activate cholinergic synapses by releasing Ach into the synaptic cleft – Drug binds to Ach receptors, enhancing action potential – Drug inactivated by AchE Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Indirect Cholinergic Agonists • Drug binds AchE, preventing Ach from being destroyed – Increases amount of Ach remaining in synaptic cleft • Results in a greater effect Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Effects of Muscarinic Agonists • Increase degree of smooth muscle tone and contractions of the GI tract • Stimulate smooth muscle of the urinary tract • Stimulate most exocrine glands • Cause contraction of the iris sphincter • Contraction of bronchial smooth muscle Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Precautions • Do not administer to patients with: – Suspected obstructive disease of the gastrointestinal or genitourinary tract – Asthma or COPD • Monitor patients for reflex tachycardia – Particularly hyperthyroid or cardiovascular patients Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Bethanechol Chloride • Therapeutic classification – Drug to treat urinary retention • Pharmacologic classification – Cholinergic agonist, muscarinic agonist (direct acting) • Mechanism of action – Structurally similar to Ach – Interacts directly with muscarinic receptors to cause body responses typical of parasympathetic stimulation – Selective for muscarinic receptors • Indications – Restores smooth muscle tone & peristalsis following surgery – Nonobstructive urinary retention Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Bethanechol Chloride • Precautions/Contraindications – – – – – – – – Suspected bowel obstruction Recent GI surgery Suspected urinary obstruction Recent bladder surgery Asthma, COPD Recent MI, Severe bradycardia, hypotension, or hypertension Hyperthyroidism Peritonitis, epilepsy, Parkinson’s disease Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Bethanechol Chloride • Nursing responsibilities – Monitor BP and pulse for at least 1 hour following administration – Monitor for early signs of overdose – Document the patient’s response to the medication & report failure to the prescriber – Monitor for signs of respiratory distress – Monitor for hypotension, falls while ambulating, and blurred vision Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Indirect Acting (Anticholinesterase Agents) • Common side effects – Involuntary contraction or twitching of muscles, nausea/vomiting, miosis, increased salivation • Serious adverse effects – Bradycardia, hypotension, dyspnea, seizures, bronchospasm, cholinergic crisis, death due to paralysis of respiratory muscles Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Potential Uses for AchE Inhibitors • Alzheimer’s disease • Glaucoma • Protect against bioterrorist attack with nerve gases • Myasthenia gravis Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban PHARMACOLOGY CONNECTIONS TO NURSING PRACTICE Second Edition CHAPTER 18 Cholinergic Antagonists Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Muscarinic Antagonists Muscarinic antagonists have been used for a diverse number of conditions, but they are rarely the drugs of choice due to their adverse effects. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Muscarinic Antagonists • Primarily block receptors in the parasympathetic nervous system • May also be known as anticholinergics, cholinergic blockers, muscarinic antagonists, or parasympatholytics • Work by competing with Ach for binding at muscarinic receptors, allowing sympathetic activation to dominate Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Muscarinic Antagonists • Are used for their parasympathetic actions – Dilation of the pupils – Increased heart rate – Drying of secretions – Bronchodilation Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Uses of Muscarinic Antagonists • • • • • • • • GI disorders such as IBS Ophthalmic procedures Cardiac rhythm disorders Adjuncts to anesthesia to decrease secretions Asthma for bronchodilation effects Antidotes for poisoning from muscarinic drugs Neurogenic bladder; Urge incontinence Parkinson’s disease Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Uses of Muscarinic Antagonists • Antidotes for poisoning from muscarinic drugs • Urge incontinence • Parkinson’s disease Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban 34 Examples of Anticholinergic agents • tolterodine (Detrol) – It is a competitive antagonist of muscarinic receptors. It a demonstrates selectivity for urinary bladder receptors over salivary receptors. – Used in the treatment of patients with an overactive bladder with symptoms of urinary frequency, urgency, or urge incontinence • scopolamine (Transderm-Scōp) – Blocks the action of ACh at parasympathetic sites in smooth muscle, secretory glands and the CNS – Used preoperatively for control of secretions, and motion sickness Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Side effects of cholinergic 35 blocking agents Cardiovascular: Increased heart rate, dysrhythmias CNS: CNS excitation, restlessness, irritability, disorientation, hallucinations, delirium Eye: dilated pupils, decreased visual accommodation, increased intraocular pressure GI: decreased salivation, gastric secretions, motility GU: urinary retention Glandular: decreased sweating Respiratory: decreased bronchial secretions Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Potential Adverse Effects • • • • • • Urinary retention Xerostomia Tachycardia CNS stimulation Dry eyes Photophobia Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Nursing considerations 37 • Dry mouth is a common side effect – Brush teeth regularly/frequent dental visits – Chew gum or suck on hard candy (sugar free) – Artificial saliva • Patients should be careful when engaging in driving or operating heavy machinery – May experience blurred vision • Patients may experience increased sensitivity to light • At risk for constipation- increase fluid, fiber, etc. • Older patients should avoid strenuous activities and high temperatures – Risk for heat stroke or hyperthermia Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Atropine • Therapeutic classification – Agent for bradycardia, antidote for muscarinic agonist OD • Pharmacologic classification – Anticholinergic, muscarinic antagonist • Mechanism of action – – – – Blocks parasympathetic activation by Ach Induces symptoms of fight-or-flight response Specific to muscarinic receptors at therapeutic doses May block nicotinic receptors at high doses One of the most important actions INCREASE HR, CPR Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Atropine • Indications – Treats bradycardia or as an antidote for muscarinic overdose – Limited use secondary to side effects – Can work as adjunct therapy in surgical procedures to decrease respiratory secretions – Used for overdose of cholinergic agonists, including organophosphate insecticides and muscarinic mushrooms Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Atropine • Common adverse effects – Drying of oral/nasal mucosa – Constipation – Urinary retention – Increased HR – Blurred vision – Photophobia • Serious adverse effects – VF – Delirium – Coma Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Atropine • Nursing responsibilities – Monitor vital signs, particularly paradoxical bradycardia – Monitor intake and output – Assess CNS status for changes – Monitor for atropine fever – Monitor ophthalmic pressures during procedures Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban PHARMACOLOGY CONNECTIONS TO NURSING PRACTICE Second Edition CHAPTER 19 Andrenergic Agonists Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban 43 What are adrenergic receptors? • Site where adrenergic drugs (neurotransmitters) bind and produce their effects • Catecholamine's (neurotransmitters) Act on receptor sites throughout the body – known as adrenergic receptors. – Two major types of receptors-alpha and beta. – Two subtypes for each : alpha 1 and alpha 2 beta 1 and beta 2 Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Adrenergic receptors • Act on: • Alpha 1- on postsynaptic effector cells – Tissue – Muscle – Organ • Alpha 2- on presynaptic nerve terminals (actually on the nerve) – Control release of neurotransmitters • Beta 1 – postsynaptic effector cells – Heart • Beta 2 – postsynaptic effector cells- smooth muscles of: – Bronchioles – Arterioles – Visceral organs (e.g. uterus) Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Adrenergic receptor responses to stimulation Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban 45 Sympathomimetics • Exert effects via two mechanisms – Directly Binding to and activating adrenergic receptors Epinephrine, norepinephrine, dopamine – Indirectly Increasing amount of norepinephrine available at adrenergic synapses Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Adrenergic Agonists • Activate sympathetic receptors in sympathetic nervous system • Induce fight-or-flight response • Two receptor types – Alpha – Beta • Include norepinephrine, epinephrine, dopamine Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Alpha1-Receptor Agonists • Generally prescribed for nasal congestion and hypotension • May be used to produce mydriasis during ophthalmic exams Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Adrenergic nasal Decongestants • pseudoephedrine (Sudafed, Afrin) – Alpha-adrenergic activity is used for causing vasoconstriction in the nasal mucosa – easing nasal breathing and reducing nasal secretions – Side effects-anxiety, tremors, dizziness, headache, insomnia, nervousness, palpitations – Nursing-Use cautiously in patients with hypertension, cardiac disease, diabetes, glaucoma, hyperthyroidism, and prostatic hyperplasia • Rebound congestion may occur with frequent or prolonged use • Tell patients not to take drug within 2 hours of bedtime because it can cause insomnia Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Beta1-Receptor Agonists • Critical care drugs – Heart attack – Heart failure – Shock • Have powerful affects on heart Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Beta2-Receptor Agonists • Used to treat asthma • Reduce preterm labor contractions of uterus Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Epinephrine (Adrenalin) • Therapeutic classification – Antishock and antianaphylaxis agent, bronchodilator • Pharmacologic classification – Nonselective adrenergic agonist, catecholamine • Pregnancy category C Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Epinephrine (Adrenalin) • Mechanism of action – Stimulates both alpha- and betaadrenergic receptors throughout body – Action creates fight-or-flight response Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Epinephrine (Adrenalin) • Indications – Drug of choice in CPR – Reversal of anaphylaxis – Added to local anesthetics to constrict local vessels – Adjunct therapy for open-angle glaucoma – To reduce nasal congestion Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Epinephrine (Adrenalin) • Precautions/Contraindications – Hypersensitivity to other adrenergic agonists – Closed-angle glaucoma – Severe shock – Dysrhythmias – CAD – Labor – HTN or hyperthyroidism Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Epinephrine (Adrenalin) • Common adverse effects – – – – – – – Nervousness Tremors Palpitations Tachycardia Dizziness Headache Stinging at site • Serious adverse effects – – – – – Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban HTN Dysrhythmias Pulmonary edema Cardiac arrest Intense CNS stimulations Prototype Drug Epinephrine (Adrenalin) • Nursing responsibilities – Focus assessment on underlying problem – Assess for preexisting conditions – Establish baseline vital signs – Closely monitor respiratory status – Use cardiac monitor/resuscitation equipment Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Epinephrine (Adrenalin) • Nursing responsibilities – Monitor BP closely – Inform prescriber of changes in I&O – Monitor for hypoglycemia – Examine ocular and nasal mucosa Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Vasoactive adrenergics • Used to support a failing heart or to treat shock • Very potent, quick-acting, and their effects quickly cease when they are stopped – epinephrine (Adrenaline), alpha & beta adrenergic, treat shock – Dopamine- (Intropin) -beta1 adrenergic, IV only, to raise B/P, – Norepinephrine- (Levophed) Alpha & Beta adrenergic – dobutamine (Dobutrex)-beta 1 adrenergic, to treat cardiac decompression Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Adrenergic drugs side/adverse effects 60 • Alpha: – headaches, restlessness, excitement, insomnia, euphoria – Cardiovascular: chest pain, vasoconstriction, HTN, tachycardia, dysrhythmias – Anorexia, dry mouth, N/V, taste changes • Beta: – Mild tremors, H/A, nervousness, dizziness – Cardiovascular: increased heart rate, palpitations, dysrhythmias, B/P fluctuations – Sweating, N/V, muscle cramps Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban PHARMACOLOGY CONNECTIONS TO NURSING PRACTICE Second Edition CHAPTER 20 Andrenergic Antagonists Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Alpha1-Adrenergic Antagonists • Receptors located on smooth muscle of heart, genitourinary and gastrointestinal systems, and brain • Most important action of these agents is on arterial smooth muscle and cardiovascular system • Blockade of alpha receptors dilates blood vessels, lowering blood pressure Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Figure 20.1 Pharmacologic effects and indications of adrenergic antagonists: (a) blockade of alpha1 receptors; (b) blockade of beta1 receptors; (c) blockade of beta2 receptors. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Adrenergic Blocking agents • Antagonists- bind to adrenergic receptors inhibiting or blocking stimulation of the sympathetic nervous system, AKA sympatholytics – Alpha blockers- block at the alpha adrenergic receptor. Causes vasodilation, decreased B/P, miosis (constriction of pupil), suppressed ejacuation – Beta blockers– Alpha-beta blockers Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Alpha Blockers 65 • Interrupt or block the stimulation of the SNS at the alpha-adrenergic receptor – Leads to vasodilatation, decreased blood pressure, constriction of the pupil (miosis), or suppressed ejaculation – Some alpha blockers (ergots) cause vasoconstriction • Competitive Blockade- compete for sites with NE. Occupy the site before the neurotransmitter NE or push off the NE- reversible blockade. • Noncompetitive Blockade- irreversible, forms a bond at the receptor. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban When do we use alpha-blockers? • Migraines – Ergot alkaloid – ergotamine tartrate • Constricts arterioles in the brain • Control postpartum bleeding and increases uterine contractions – * oxytocin (Pitocin) Induces local vasoconstriction • Hypertension – doxazosin, prazosin, terazosin, tamsulosin • Alpha-blocker that causes both arterial and venous dilation • Reduces peripheral vascular resistance • Benign Prostatic hyperplasia – Tamsulin (Flomax)- reduces ctx of bladder neck & prostate portion of the urethra Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Prazosin (Minipress) • Common adverse effects – First-dose phenomenon can cause syncope – ED (priapism) Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Prazosin (Minipress) • Nursing responsibilities – Initial dose to be given at bedtime – Give medication with food – Assess for first-dose phenomenon – Monitor BP – Assess for full therapeutic effect Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Side effects of alpha-blockers • Cardiovascular: palpitations, orthostatic hypotension, tachycardia, edema, dysrhythmias, chest pain • CNS: dizziness, headache, drowsiness, anxiety, depression, vertigo, weakness, numbness, fatigue • GI: nausea, vomiting, diarrhea, constipation, abdominal pain • Other: Incontinence, nose bleeding, tinnitus, dry mouth, pharyngitis, rhinitis Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Management of overdose of alphablockers • Acute overdose need to empty stomach (i.e. ipecac syrup, gastric lavage) • Activated charcoal to bind the drug and remove it from the stomach and circulation • Treat symptoms • ABC Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Beta-blockers 71 • Block SNS stimulation of the beta-adrenergic receptors by competing with the endogenous catecholamines; norepinephrine and epinephrine • May be selective (beta 1-blocking agents) – Cardioselective beta Blockers – Block the beta-adrenergic receptor site on the surface of the heart • Nonselective (beta 1 & beta 2- blocking agents), block cardiac and respiratory and smooth muscle of blood vessels • Cardioprotective effects Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Beta Blockers • Cardioselective: • Non-selective: • atenolol (Tenormin) • – Used to prevent future myocardial infarctions (MI) in patients who have had an MI, hypertension, and angina • propanolol (Inderal) – Used in treatment of hypertension, angina, tachydysrhythmias, pheochromocytoma, migraines • acebutolol (Sectral) – Used for treatment of hypertension, ventricular and supraventricular dysrhythmias, and angina labetalol (Nomodyne and Trandate) – Used in treatment of severe hypertension and hypertensive emergencies – Can block both alpha- and betaadrenergic receptors • metoprolol (Lopressor and Toprol XL) – Used in post MI patients, increases survival in patients who had a MI 72 • Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban carvedilol (Coreg) – Used in treatment of heart failure (slows progression of heart failure), hypertension, and angina Beta-Adrenergic Antagonists • Selective – Block only beta1 receptors – Cardioselective – Fewer noncardiac side effects – Little effect on bronchial smooth muscle – Can be safely given to clients with asthma and COPD Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Beta-Adrenergic Antagonists • Nonselective – Block beta1 and beta2 receptors – Produce more side effects than selective beta1 antagonists – Serious side effect is bronchoconstriction – Caution in patients with COPD or asthma Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Side effects of beta blockers • Cardiovascular: AV block, bradycardia, heart failure, peripheral vascular insufficiency • CNS: dizziness, mental depression, lethargy, hallucinations • GI: nausea, dry mouth, vomiting, constipation, diarrhea, cramps • Other: impotence, rash, alopecia, bronchospasms Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Management of overdose/toxicity of beta-blockers 76 • Acute overdose need to empty stomach (i.e. ipecac syrup, gastric lavage) • Treat symptoms and provide supportive care – atropine to treat bradycardia – Vasopressors for hypotension – diazepam (Valium) to treat seizures Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban 77 Nursing Implications/Teach patient: – Wear medical alert bracelet, necklace, etc. – Information on medications taken in purse, wallet, etc. – Never abruptly stop medications (may lead to rebound hypertension). Don’t double up meds – Adrenergic blocking agents- avoid caffeine & other CNS stimulants – Avoid Alcohol- leads to vasodilatation increasing hypotension & orthostatic Hypotension – Rise slowly – Report weight gain, SOB, excessive fatigue, syncope, confusion, depression, hallucinations, palpitations. Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Similar Drugs • • • • • • • Carteolol (Cartrol, Ocupress) Carvedilol (Coreg) Labetalol (Normodyne, Trandate) Metipranolol (OptiPranolol) Nadolol (Corgard) Penbutolol (Levatol) Pindolol (Visken) Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Metoprolol (Lopressor, Toprol) • Indications – HTN – Off-label uses Stable, symptomatic heart failure Essential tremor Migraine prophylaxis Atrial dysrhythmias • Precautions/Contra indications – Preexisting cardiac disease – Cardiogenic shock – Severe bradycardia – Heart block greater than 1st degree – Severe hepatic disease – Asthma Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Metoprolol (Lopressor, Toprol) • Common adverse effects – – – – – – – Nausea/vomiting Dizziness Fatigue Insomnia Bradycardia Heartburn Dyspnea • Serious adverse effects – Agranulocytosis – Laryngospasm – Complete heart block – Thyroid storm – Dysrhythmias – Severe HTN – MI Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Metoprolol (Lopressor, Toprol) • Nursing responsibilities – Assess vital signs – Monitor BP, HR, ECG during IV administration – Assess BP readings for adequacy and maximal drug effect – Monitor for symptoms of impending heart failure – Watch for symptoms of depression Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Metoprolol (Lopressor, Toprol) • Nursing responsibilities – Watch for masked hyperthyroidism – Record I&O, daily weight, bilateral breath sounds – Take radial pulse – Do not omit, increase, or decrease dosage – Avoid late evening doses Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Metoprolol (Lopressor, Toprol) • Nursing responsibilities – Report Visual problems Cold, painful, tender feet, or hands Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Prototype Drug Metoprolol (Lopressor, Toprol) • Caution: – Diabetics – Hazardous activities – Discontinue drug slowly – Do not breast feed without consulting provider Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban Similar Drugs • • • • • • Acebutolol (Sectral) Atenolol (Tenormin) Betaxolol (Betoptic, Kerlone) Bisoprolol (Zebeta, Ziac) Esmolol (Brevibloc) Nebivolol (Bystolic) Pharmacology: Connections to Nursing Practice, Second Edition Michael Patrick Adams • Carol Quam Urban
