Mosby items and derived items © 2005, 2002 by Mosby, Inc. CHAPTER 36 Bronchodilators and Other Respiratory Agents

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Diseases of the Lower Respiratory Tract Bronchial asthma Emphysema Chronic bronchitis COPD Cystic fibrosis Infant respiratory distress syndrome

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Bronchial Asthma Recurrent and reversible shortness of breath Occurs when the airways of the lungs become narrow as a result of: –Bronchospasms –Inflammation of the bronchial mucosa –Edema of the bronchial mucosa –Production of viscid mucus

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Bronchial Asthma (cont'd) Alveolar ducts/alveoli remain open, but airflow to them is obstructed Symptoms –Wheezing –Difficulty breathing

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Asthma Three categories Allergic Idiopathic Mixed allergic/idiopathic

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Asthma (cont'd) Status asthmaticus –Prolonged asthma attack that does not respond to usual medical therapy –Medical emergency

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Chronic Bronchitis Continuous inflammation of the bronchi and bronchioles Often occurs as a result of prolonged exposure to bronchial irritants

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Emphysema Air spaces enlarge as a result of the destruction of alveolar walls The surface area where gas exchange takes place is reduced Effective respiration is impaired

Mosby items and derived items © 2005, 2002 by Mosby, Inc. COPD Chronic obstructive pulmonary disease Applies to chronic bronchitis and emphysema Obstruction is constant

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Agents Used to Treat Asthma Long-term control –Antileukotrienes –Cromolyn –Inhaled steroids –Long-acting beta 2 -agonists Quick relief –Intravenous systemic corticosteroids –Short-acting inhaled beta 2 -agonists –Ipratropium –Nedocromil –theophylline

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Bronchodilators and Respiratory Agents Bronchodilators –Xanthine derivatives –Beta-adrenergic agonists Anticholinergics Antileukotrienes Corticosteroids Mast cell stabilizers

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Bronchodilators: Xanthine Derivatives Plant alkaloids: caffeine, theobromine, and theophylline Only theophylline is used as a bronchodilator –Examples: Aminophylline Dyphilline Oxtriphylline theophylline (Bronkodyl, Slo-bid, Theo- Dur, Uniphyl)

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Xanthines: Action Smooth muscle relaxation Bronchodilation Increased airflow

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Xanthines: Drug Effects CNS stimulation Cardiovascular stimulation: increased force of contraction increased HR increased cardiac output increased blood flow to the kidneys (diuretic effect)

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Xanthines: Indications Dilation of airways in asthmas, chronic bronchitis, and emphysema Mild to moderate cases of acute asthma Adjunct agent in the management of COPD

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Xanthines: Side Effects Nausea, vomiting, anorexia Gastroesophageal reflux during sleep Sinus tachycardia, extrasystole, palpitations, ventricular dysrhythmias Transient increased urination

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Bronchodilators: Beta-Agonists Large group, sympathomimetics Used during acute phase of asthmatic attacks Quickly reduce airway constriction and restore normal airflow Stimulate beta 2 -adrenergic receptors throughout the lungs

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Bronchodilators: Beta-Agonists Three types Nonselective adrenergics –Stimulate alpha-, beta 1 - (cardiac), and beta 2 - (respiratory) receptors –Example: epinephrine Nonselective beta-adrenergics –Stimulate both beta 1 - and beta 2 -receptors –Example: isoproterenol (Isuprel)

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Bronchodilators: Beta-Agonists (cont'd) Three types (cont'd) Selective beta 2 drugs –Stimulate only beta 2 -receptors –Example: albuterol

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Beta-Agonists: Mechanism of Action Begins at the specific receptor stimulated Ends with the dilation of the airways –relaxes smooth muscles of the airway and results in bronchial dilation and increased airflow

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Beta-Agonists: Indications Relief of bronchospasm related to asthma, bronchitis, and other pulmonary diseases Useful in treatment of acute attacks as well as prevention Used in hypotension and shock Used to produce uterine relaxation to prevent premature labor Hyperkalemia—stimulates potassium to shift into the cell

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Beta-Agonists: Side Effects Alpha-Beta insomnia restlessness anorexia vascular headache (epinephrine) hyperglycemia tremor cardiac stimulation

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Beta-Agonists: Side Effects Beta 1 and Beta 2 (isoproterenol) Cardiac stimulation Tremor Vascular headaches Hypotension Anginal pain

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Beta-Agonists: Side Effects Beta 2 (albuterol) Hypotension OR hypertension Vascular headaches Tremor

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications Encourage patients to take measures that promote a generally good state of health in order to prevent, relieve, or decrease symptoms of COPD –Avoid exposure to conditions that precipitate bronchospasms (allergens, smoking, stress, air pollutants) –Adequate fluid intake –Compliance with medical treatment –Avoid excessive fatigue, heat, extremes in temperature, caffeine

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications Encourage patients to get prompt treatment for flu or other illnesses, and to get vaccinated against pneumonia or flu Encourage patients to always check with their physician before taking any other medication, including OTCs

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications Perform a thorough assessment before beginning therapy, including: –Skin color –Baseline vital signs –Respirations (should be 24 breaths/min) –Respiratory assessment, including PO 2 –Sputum production –Allergies –History of respiratory problems –Other medications

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications Teach patients to take bronchodilators exactly as prescribed Ensure that patients know how to use inhalers and MDIs, and have the patients demonstrate use of devices Monitor for side effects

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications Monitor for therapeutic effects –Decreased dyspnea –Decreased wheezing, restlessness, and anxiety –Improved respiratory patterns with return to normal rate and quality –Improved activity tolerance Decreased symptoms and increased ease of breathing

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications: Xanthine Derivatives Contraindications: history of PUD or GI disorders Cautious use: cardiac disease Timed-release preparations should not be crushed or chewed (causes gastric irritation)

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications: Xanthine Derivatives Report to physician: –Palpitations –Nausea –Vomiting –Weakness –Dizziness –Chest pain –Convulsions

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications: Xanthine Derivatives Be aware of drug interactions with cimetidine, oral contraceptives, allopurinol Large amounts of caffeine can have deleterious effects

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications: Beta-Agonist Derivatives Albuterol, if used too frequently, loses its beta 2 -specific actions at larger doses As a result, beta 1 -receptors are stimulated, causing nausea, increased anxiety, palpitations, tremors, and increased heart rate

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Nursing Implications: Beta-Agonist Derivatives Patients should take medications exactly as prescribed, with no omissions or double doses Patients should report insomnia, jitteriness, restlessness, palpitations, chest pain, or any change in symptoms

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Inhalers: Patient Education For any inhaler prescribed, ensure that the patient is able to self-administer the medication –Provide demonstration and return demonstration –Ensure the patient knows the correct time intervals for inhalers –Provide a spacer if the patient has difficulty coordinating breathing with inhaler activation

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Anticholinergics: Mechanism of Action Acetylcholine (ACh) causes bronchial constriction and narrowing of the airways Anticholinergics bind to the ACh receptors, preventing ACh from binding Result: bronchoconstriction is prevented, airways dilate

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Anticholinergics ipratropium bromide (Atrovent) is the only anticholinergic used for respiratory disease Slow and prolonged action Used to prevent bronchoconstriction NOT used for acute asthma exacerbations!

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Anticholinergics (cont'd) Side effects: Dry mouth or throat Gastrointestinal distress Headache Coughing Anxiety No known drug interactions

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antileukotrienes Also called leukotriene receptor antagonists (LRTAs) Newer class of asthma medications Three subcategories of agents

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antileukotrienes (cont'd) Currently available agents –montelukast (Singulair) –zafirlukast (Accolate) –zileuton (Zyflo)

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Leukotrienes Substances in the body that cause inflammation, bronchoconstriction, and mucus production Result: coughing, wheezing, shortness of breath

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antileukotrienes: Mechanism of Action Prevent inflammation in the lungs so asthma symptoms are relieved

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antileukotrienes: Drug Effects Keep bronchial airways relaxed (open) Decrease mucus secretion Prevent vascular permeability Preventing inflammation

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antileukotrienes: Indications Prophylaxis and chronic treatment of asthma in adults and children older than age 12 NOT meant for management of acute asthmatic attacks Montelukast (Singulair) is approved for use in children ages 2 and older

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antileukotrienes: Side Effects zileuton Headache Dyspepsia Nausea Dizziness Insomnia Liver dysfunction montelukast has fewer side effects zafirlukast Headache Nausea Diarrhea Liver dysfunction

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antileukotrienes: Nursing Implications Ensure that the drug is being used for chronic management of asthma, not acute asthma Teach the patient the purpose of the therapy Improvement should be seen in about 1 week

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Antileukotrienes: Nursing Implications Check with physician before taking any OTC or prescribed medications—many drug interactions Assess liver function before beginning therapy Medications should be taken every night on a continuous schedule, even if symptoms improve

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Corticosteroids Antiinflammatory Used for chronic asthma Do not relieve symptoms of acute asthmatic attacks Oral or inhaled forms Inhaled forms reduce systemic effects May take several weeks before full effects are seen

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Corticosteroids: Mechanism of Action Stabilize membranes of cells that release harmful bronchoconstricting substances These cells are leukocytes, or white blood cells Also increase responsiveness of bronchial smooth muscle to beta-adrenergic stimulation

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Inhaled Corticosteroids beclomethasone dipropionate (Beclovent, Vanceril) triamcinolone acetonide (Azmacort) dexamethasone sodium phosphate (Decadron Phosphate Respihaler) flunisolide (AeroBid) fluticasone (Flovent, Flonase)

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Inhaled Corticosteroids: Indications Treatment of bronchospastic disorders that are not controlled by conventional bronchodilators NOT considered first-line agents for management of acute asthmatic attacks or status asthmaticus

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Inhaled Corticosteroids: Side Effects Pharyngeal irritation Coughing Dry mouth Oral fungal infections Systemic effects are rare because of the low doses used for inhalation therapy

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Inhaled Corticosteroids: Nursing Implications Contraindicated in patients with psychosis, fungal infections, AIDS, TB Cautious use in patients with diabetes, glaucoma, osteoporosis, PUD, renal disease, HF, edema Teach patients to gargle and rinse the mouth with water afterward to prevent the development of oral fungal infections

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Inhaled Corticosteroids: Nursing Implications Abruptly discontinuing these medications can lead to serious problems If discontinuing, should be weaned for 1 to 2 weeks, only if recommended by physician Report any weight gain of more than 5 pounds a week or the occurrence of chest pain

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Mast Cell Stabilizers cromolyn (NasalCrom, Intal) nedocromil (Tilade)

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Mast Cell Stabilizers (cont'd) Indirect-acting agents that prevent the release of the various substances that cause bronchospasm Stabilize the cell membranes of inflammatory cells (mast cells, monocytes, macrophages), thus preventing release of harmful cellular contents No direct bronchodilator activity Used prophylactically

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Mast Cell Stabilizers: Indications Adjuncts to the overall management of asthma Used solely for prophylaxis, NOT for acute asthma attacks Used to prevent exercise-induced bronchospasm Used to prevent bronchospasm associated with exposure to known precipitating factors, such as cold, dry air or allergens

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Mast Cell Stabilizers: Side Effects Coughing Sore throat Rhinitis Bronchospasm Taste changes Dizziness Headache

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Mast Cell Stabilizers: Nursing Implications For prophylactic use only Contraindicated for acute exacerbations Not recommended for children younger than age 5 Therapeutic effects may not be seen for up to 4 weeks Teach patients to gargle and rinse the mouth with water afterward to minimize irritation to the throat and oral mucosa