Bronchodilators and Other Respiratory Agents Chapter 16 Bronchodilators and Other Respiratory Agents

Bronchodilators Medications used to relax and open the airways Open or maintain the bronchial airways Treat several disease syndromes Chronic obstructive pulmonary disease Asthma Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Classes of Bronchodilators Sympathomimetic agents Xanthine bronchodilators Anticholinergics Leukotriene receptor antagonists 5-lipoxygenase inhibitors Mast cell stabilizers Corticosteroids Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Sympathomimetics Beta2-adrenergic receptors Used during the acute phase of asthmatic attacks Quickly reduce airway constriction and restore normal airflow Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Uses for Sympathomimetics Treat acute attacks as well as prevent attacks Quickly reduce airway constriction and restore normal airflow Relief of bronchospasm, bronchial asthma, bronchitis, and other pulmonary diseases Treat hypotension and shock Produce uterine relaxation to prevent premature labor Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Sympathomimetic Agents Nonselective adrenergics Stimulate alpha1, beta1 (cardiac), and beta2 (respiratory) receptors Example: epinephrine (continues) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Sympathomimetic Agents (continued) Sympathomimetic Agents Nonselective beta-adrenergics Stimulate both beta1 and beta2 receptors Example: isoproterenol (Isuprel) Selective beta2 drugs Stimulate only beta2 receptors Example: albuterol (continues) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Sympathomimetic Agents (continued) Sympathomimetic Agents Frequent use leads to beta1 receptors being stimulated Albuterol loses its action General side effects Nausea, increased anxiety, palpitations, tremors, and increased heart rate Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Xanthines Chemical class of agents Oldest class of bronchodilators Contain caffeine Oldest class of bronchodilators Used in ancient times Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Xanthine Bronchodilators: Mechanism of Action Increase levels of energy-producing cAMP Inhibit phosphodiesterase Enzyme that breaks down cAMP Result Smooth muscle relaxation Bronchodilation Increase airflow (oxygen/carbon dioxide) in the lungs Cause cardiac life-threatening side effects Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Xanthine Derivatives: Side Effects Nausea, vomiting, anorexia Gastroesophageal reflux during sleep Sinus tachycardia, extrasystole, palpitations, ventricular dysrhythmias Transient increased urination Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Anticholinergics: Mechanism of Action Acetylcholine (ACh) causes bronchial constriction. Anticholinergics bind to the ACh receptors, preventing ACh from binding. Result: bronchoconstriction is prevented, airways dilate Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Anticholinergic Bronchodilators Ipratropium bromide (Atrovent) Tiotropium bromide (Spiriva HandiHaler) Actions Local effects Slow and prolonged action Used to prevent bronchoconstriction Not used for acute asthma exacerbations! Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Anticholinergics: Side Effects Usually not absorbed systemically If absorbed, have the potential to produce: Dry mouth or dry throat Gastrointestinal distress Headache Coughing Anxiety Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Leukotriene Receptor Antagonists Directly prevent bronchoconstriction Developed to treat asthma Popular and effective Leukotrienes are inflammatory molecules Released by mast cells Cause the bronchials to contract Development of edema in the lungs (continues) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Leukotriene Receptor Antagonists (continued) Leukotriene Receptor Antagonists By blocking leukotrienes: Prevent smooth muscle contraction of the bronchial airways Decrease mucus secretion Prevent vascular permeability Decrease neutrophil and leukocyte infiltration to the lungs (continues) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Leukotriene Receptor Antagonists (continued) Leukotriene Receptor Antagonists Currently available agents: Montelukast (Singulair) Zafirlukast (Accolate) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Leukotriene Receptor Antagonists: Side Effects Headache Nausea Diarrhea Liver dysfunction Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Leukotriene Receptor Antagonists: Client Education Educate the client. Use for chronic management of asthma, not acute asthma Improvement should be seen in about 1 week Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

5-Lipoxygenase Inhibitors New class of leukotriene receptor antagonists Action Inhibit the formation of leukotrienes Used to inhibit some cancer growth Outcome Prevent lung inflammation Example One agent: Zileuton Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Mast Cell Stabilizers Used prophylactically No direct bronchodilator activity Indirect-acting Stabilize the cell membranes of the inflammatory cells–mast cells, monocytes, macrophages Prevent release of harmful cellular contents (continues) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

(continued) Mast Cell Stabilizers Adjuncts to the overall management of clients with lung disease Prevent bronchospasm when exposed to: Cold air Exercise Allergens Dry air Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Mast Cell Stabilizers: Examples Cromolyn (Nasalcrom, Intal) Nedocromil (Tilade) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Mast Cell Stabilizers: Side Effects Coughing Taste changes Sore throat Dizziness Rhinitis Headache Bronchospasm Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Inhaled Corticosteroids Anti-inflammatory Inhaled forms Reduce systemic effects Used for chronic asthma Does not relieve acute asthma (continues) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Inhaled Corticosteroids (continued) Inhaled Corticosteroids Stabilize membranes of cells that release harmful bronchoconstricting substances Also increase responsiveness of bronchial smooth muscle to beta-adrenergic stimulation Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Inhaled Corticosteroids: Examples Beclomethasone dipropionate (Beclovent, Vanceril) Triamcinolone acetonide (Azmacort) Flunisolide (AeroBid) Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Inhaled Corticosteroids: Side Effects Pharyngeal irritation Coughing Dry mouth Oral fungal infections Systemic effects are rare Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Respiratory Agents Combination product Fluticasone propionate and salmeterol (Advair): a dry powder in a circular diskus Salmeterol: long-acting bronchodilator Corticosteroid: anti-inflammatory agent Used daily Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

Respiratory Agents: Client Education Instruct clients to: Receive flu and pneumonia vaccination Receive prompt treatment for any illness Check with health care provider before taking other medications Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.