Adrenergic Drugs Topical Outline 1.4a

“Neuro” (+) ( - ) Adrenergic Cholinergic Drugs Drugs Adrenergic 18 Cholinergic Drugs 20 (+) Adrenergic Blocking Drugs 19 Cholinergic Blocking Drugs 21 ( - )

Nursing Pharmacology Allergies Respiratory System Drugs Asthma HTN Heart Failure Cardiac System Drugs Angina, MI Dysrhythmias Coags Diuretics Anti-Microbial Drugs Inflammation Nursing Pharmacology Bacterial Fungal Viral Nursing Process Pharmacokinetics Pharmacodynamics Neurologic System Drugs Anxiety Seizures Psychoses Analgesic Drugs Pain Endocrine System Drugs Pituitary Diabetes PUD Gastrointestinal System Drugs GI

Learning Outcomes 1. Identify the basic functions of the nervous system. 2. Identify divisions of the peripheral nervous system. 3. Compare and contrast the actions of the sympathetic and parasympathetic divisions of the autonomic nervous system. 4. Compare and contrast the types of responses that occur when drugs activate (or block) alpha1-, alpha2-, beta1-, or beta2-adrenergic receptors, and nicotinic or muscarinic receptors. 5. Discuss the classification and naming of autonomic drugs based on four possible actions. 6. Describe the nurse’s role in the pharmacological management of patients receiving drugs affecting the autonomic nervous system. 7. Use the nursing process to care for patients receiving adrenergic agents, adrenergic-blocking agents, cholinergic agents, and cholinergic-blocking agents. (cholinergic receptors)

Key Terminology adrenergic Agonist Alpha receptors Beta receptors Antagonist catecholamine Neurotransmitters (NE & Ach) Sympathomimetic Vasoconstriction Vasodilation vasopressor Inotropic (+ and -) Chronotropic (+ and -) Dromotropic (+ and -) ….more

Adrenergic Drugs Drugs that stimulate the sympathetic nervous system (SNS) Also known as: Adrenergic agonists Sympathomimetics Adrenergic drugs are those that stimulate the ______________nervous system. Adrenergic drugs are also known as a___________ a___________ or s_____________.

The Nervous System Central Peripheral Somatic Autonomic 1 2 1 2 Brain Spinal Cord Somatic (skeletal muscle) Autonomic Parasympathetic (cholinergic) ACh Sympathetic (adrenergic) NE Add in the nervous system flash here… zzzzzzzzzzzzzz Alpha Beta 1 2 1 2

Characteristics of Adrenergic Drugs Mimic the effects of SNS neurotransmitters (catecholamines) Norepinephrine (NE) Epinephrine (EPI) Dopamine

Adrenergic Receptors Located throughout the body Are receptors for the sympathetic neurotransmitters Alpha-adrenergic receptors Beta-adrenergic receptors Dopaminergic receptors: respond only to dopamine

Alpha-Adrenergic Receptors Divided into alpha1 and alpha2 receptors Differentiated by their location on nerves

Alpha-Adrenergic Receptors (cont’d) Located on postsynaptic effector cells (the cell, muscle, or organ that the nerve stimulates) Alpha2-adrenergic receptors Located on presynaptic nerve terminals (the nerve that stimulates the effector cells) Control the release of neurotransmitters

Alpha-Adrenergic Agonist Responses Vasoconstriction CNS stimulation

Beta-Adrenergic Receptors All are located on postsynaptic effector cells Beta1-adrenergic receptors—located primarily in the heart Beta2-adrenergic receptors—located in smooth muscle of the bronchioles, arterioles, and visceral organs B1

Beta-Adrenergic Agonist Responses Bronchial, GI, and uterine smooth muscle relaxation Glycogenolysis Cardiac stimulation

Dopaminergic Receptors An additional adrenergic receptor Stimulated by dopamine Causes dilation of the following blood vessels, resulting in increased blood flow Renal Mesenteric Coronary Cerebral

Location Receptors Stimulated Response Bladder Sphincter CARDIOVASCULAR Blood Vessels α1 β2 vasoconstriction vasodilation Cardiac Muscle β1 ↑ contractility (+ inotrope) AV Node ↑ heart rate (+ chronotrope) SA Node GASTROINTESTINAL Muscle β2 and α1 decreased motility Sphincters constriction GENITOURINARY Bladder Sphincter Penis ejaculation Uterus contraction relaxation RESPIRATORY Bronchial Muscles dilation ENDOCRINE Liver α1, β2 glycogenolysis OPHTHALMIC Pupils Dilation (mydriasis)

“Catecholamines” Substances that can produce a sympathomimetic response Endogenous Epinephrine, norepinephrine, dopamine Synthetic Dobutamine, phenylephrine

Drug Effects Stimulation of alpha-adrenergic receptors on smooth muscles results in Vasoconstriction of blood vessels Relaxation of GI smooth muscles (decreased motility) Constriction of bladder sphincter Contraction of uterus Male ejaculation Contraction of pupillary muscles of the eye (dilated pupils)

Drug Effects (cont’d) Stimulation of beta1-adrenergic receptors on the myocardium, atrioventricular (AV) node, and sinoatrial (SA) node results in cardiac stimulation (+chronotrope + inotrope) Increased force of contraction (positive inotropic effect) Increased heart rate (positive chronotropic effect) Increased conduction through AV node (positive dromotropic effect)

Drug Effects (cont’d) Stimulation of beta2-adrenergic receptors on the airways results in Bronchodilation (relaxation of the bronchi) Other effects of beta2-adrenergic stimulation Uterine relaxation Glycogenolysis in the liver Increased renin secretion in the kidneys Relaxation of GI smooth muscles (decreased motility)

Indications Treatment of asthma and bronchitis Bronchodilators: drugs that stimulate beta2-adrenergic receptors of bronchial smooth muscles, causing relaxation, resulting in bronchodilation Examples: albuterol, ephedrine, epinephrine, formoterol, levalbuterol, metaproterenol, pirbuterol, salmeterol, and terbutaline* * Used to stop premature labor—causes relaxation of uterine smooth muscle

Indications (cont’d) Treatment of nasal congestion Intranasal (topical) application causes constriction of dilated arterioles and reduction of nasal blood flow, thus decreasing congestion Alpha1-adrenergic receptors Examples: ephedrine, naphazoline, oxymetazoline, phenylephrine, and tetrahydrozoline

Indications (cont’d) Temporary relief of conjunctival congestion (eyes) Alpha-adrenergic receptors Examples: epinephrine, naphazoline, phenylephrine, tetrahydrozoline

Indications (cont’d) Reduction of intraocular pressure and dilation of pupils: treatment of open-angle glaucoma Alpha-adrenergic receptors Examples: epinephrine and dipivefrin

Vasoactive Adrenergics (Pressors, Inotropes) Also called cardioselective sympathomimetics Used to support the heart during cardiac failure or shock; various alpha and beta receptors affected

Vasoactive Sympathomimetics (Pressors, Inotropes): Examples dobutamine ephedrine fenoldopam midodrine dopamine epinephrine phenylephrine norepinephrine

Alpha-Adrenergic Adverse Effects CNS Headache, restlessness, excitement, insomnia, euphoria Cardiovascular Palpitations (dysrhythmias), tachycardia, vasoconstriction, hypertension Other Loss of appetite, dry mouth, nausea, vomiting, taste changes (rare)

Beta-Adrenergic Adverse Effects CNS Mild tremors, headache, nervousness, dizziness Cardiovascular Increased heart rate, palpitations (dysrhythmias), fluctuations in BP Other Sweating, nausea, vomiting, muscle cramps

Interactions Anesthetic drugs Tricyclic antidepressants MAOIs Antihistamines

Interactions (cont’d) Thyroid preparations Adrenergic antagonists Will directly antagonize each other, resulting in reduced effects Includes some antihypertensives

Nursing Implications Questions t o ALWAYS Ask Yourself When Monitoring the effect of any Drug: 1. Why am I giving it? (Expected Effect) 2. How do I monitor / evaluate the Effect of the Drug? 3. Is it working? 4. Is it working “too well?” Assess for allergies, asthma, and history of hypertension, cardiac dysrhythmias, or other cardiovascular disease Assess renal, hepatic, and cardiac function before treatment

Nursing Implications Perform baseline assessment of vital signs, peripheral pulses, skin color, temperature, and capillary refill; include postural blood pressure and pulse Follow administration guidelines carefully

Nursing Implications Intravenous administration Check IV site often for infiltration Use clear / crystalloid IV solutions Use an infusion pump Infuse drug slowly to avoid dangerous cardiovascular effects Monitor cardiac rhythm

Nursing Implications With chronic lung disease Instruct patients to avoid factors that exacerbate their condition Encourage fluid intake (up to 3000 mL/day) if permitted Educate patients about proper dosing, use of equipment (metered-dose inhaler [MDI], spacer, nebulizer), and equipment care

Nursing Implications Salmeterol is indicated for prevention of bronchospasms, not management of acute symptoms (“controller” vs “rescue”) Overuse of nasal decongestants may cause rebound nasal congestion or ulcerations Avoid over-the-counter or other medications because of possible interactions

Synergistic Effect Nursing Implications Administering two adrenergic drugs together may precipitate severe cardiovascular effects such as tachycardia or hypertension Synergistic Effect

Nursing Implications Monitor for therapeutic effects (cardiovascular uses) Decreased edema Increased urinary output Return to normal vital signs Improved skin color and temperature Increased LOC

Nursing Implications Monitor for therapeutic effects (asthma) Return to normal respiratory rate Improved breath sounds, fewer crackles Increased air exchange Decreased cough Less dyspnea Improved blood gases Increased activity tolerance

Question A patient is experiencing bronchospasms after running half a mile. He has several inhalers with him. Which one would be appropriate for treatment at this time? albuterol salmeterol fluticasone salmeterol and fluticasone combination (Advair Diskus) Correct answer: A Rationale: Albuterol is a beta2 agonist that is used for acute bronchospasms. Salmeterol is appropriate for prevention of bronchospasms. Fluticasone is a corticosteroid that is not effective for acute bronchospasms. Advair Diskus is used for daily maintenance, not acute exacerbations. Rationale: Albuterol is a beta2 agonist that is used for acute bronchospasms. Salmeterol is appropriate for prevention of bronchospasms. Fluticasone is a corticosteroid that is not effective for acute bronchospasms. Advair Diskus is used for daily maintenance, not acute exacerbations. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Question The bronchodilator The corticosteroid A patient has two inhalers that are due to be taken at the same time. One is a bronchodilator. The other is a corticosteroid. Which inhaler should the patient take first? The bronchodilator The corticosteroid It does not matter which one is taken first. Correct answer: A Rationale: Taking the bronchodilator first will result in a more open airway and thus allow for better penetration by the inhaled corticosteroid. Rationale: Taking the bronchodilator first will result in a more open airway and thus allow for better penetration by the inhaled corticosteroid. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Question A patient on a dobutamine drip starts to complain that he feels a “tightness” in his chest that he had not felt before. What will the nurse do first? Check the infusion site for possible extravasation Increase the infusion rate Check the patient’s vital signs Order an electrocardiogram Correct answer: C Rationale: Before anything else is done, the patient’s vital signs should be checked for alterations. The dopamine rate should not be increased. Extravasation rarely causes chest tightness. While an electrocardiogram would be prudent, it's not the priority until after the vital signs demonstrate that the patient is stable. Rationale: Before anything else is done, the patient’s vital signs should be checked for alterations. The dopamine rate should not be increased. Extravasation rarely causes chest tightness. While an electrocardiogram would be prudent, it's not the priority until after the vital signs demonstrate that the patient is stable. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Question A patient on a dobutamine drip starts to complain that her intravenous line “hurts.” The nurse checks the insertion site and sees that the area is swollen and cool. What will the nurse do first? Slow the intravenous infusion Stop the intravenous infusion Inject the area with phentolamine Notify the physician health care provider Correct answer: B Rationale: Infiltration of an intravenous solution containing an adrenergic drug may lead to tissue necrosis from excessive vasoconstriction around the intravenous site. Phentolamine is often used for the treatment of infiltration, but the first thing the nurse must do is to stop the infusion of the adrenergic drug. Slowing the medication will not stop further tissue damage. The physician should be notified, but the infusion should be stopped first. Rationale: Infiltration of an intravenous solution containing an adrenergic drug may lead to tissue necrosis from excessive vasoconstriction around the intravenous site. Phentolamine is often used for the treatment of infiltration, but the first thing the nurse must do is to stop the infusion of the adrenergic drug. Slowing the medication will not stop further tissue damage. The physician should be notified, but the infusion should be stopped first. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Question A 10-year-old child is brought to the emergency department while having an asthma attack. She is given a nebulizer treatment with albuterol. The nurse’s immediate assessment priority would be to determine the time of the child’s last meal. monitor Spo2 with a pulse oximeter. monitor the child’s temperature. provide education on asthma management. Correct answer: B Rationale: During administration of albuterol, a fast-acting beta2 agonist, the nurse should monitor the patient’s respiratory status including Spo2 (with a pulse oximeter), respiratory rate, and breath sounds to ensure that the medication is having a therapeutic effect. The other items can be handled after her respiratory status is stable. Rationale: During administration of albuterol, a fast-acting beta2 agonist, the nurse should monitor the patient’s respiratory status including Spo2 (with a pulse oximeter), respiratory rate, and breath sounds to ensure that the medication is having a therapeutic effect. The other items can be handled after her respiratory status is stable. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.